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Transcript of Spin Workshop 05, DubnaM. Contalbrigo - INFN Ferrara 1 PAX Polarized Antiproton eXperiments M....
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 1
PAXPAXPolarized Antiproton eXperimentsPolarized Antiproton eXperiments
M Contalbrigo
INFN ndash Universitagrave di Ferarra
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 2
PAX CollaborationPAX Collaboration
TIMELINE
Jan 04 Letter of Intent
May 04 QCD-PAC meeting at GSI
Aug 04 Workshop on polarized antiprotons at GSI
Jan 05 Technical Report
Mar 05 QCD-PAC meeting at GSI
178 physicists (121 in August 2004)35 institutions (15 EU 20 NON-EU)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 3
hellip the PAC would like to stress again the uniqueness of the program with polarized anti-protons and polarized protons that could become available at GSI
Evaluation by QCD-PAC (March Evaluation by QCD-PAC (March 2005)2005)
hellipthe PAC considers it is essential for the FAIR project to commit to polarized antiproton capability at this time and include polarized transport and acceleration capability in the HESR space for installation of the APR and CSR and associated hardware and the APR in the core project
We request the PAX collaboration to1) Commit to the construction and testing of the APR2) Explore all options to increase the luminosity to the value of 1031 cm-2s-
1
3) Prepare a more detailed physics proposal and detector design for each of the proposed stages These stages may include
a) 35 GeVc polarized antiprotons on a polarized proton targetb) 15 GeVc polarized antiprotons with the PANDA detector (for single spin asymmetries)c) 15 GeVc polarized antiprotons on a polarized proton target in a dedicated detector d) Collisions of 15 GeVc antiprotons with 35 GeVc polarized protons
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 4
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 5
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 6
Leading Twist Distribution Functions
12 12
L L
+f1(x)
h1(x)
proton
protonrsquo
quark
quarkrsquo
u = 12(uR + uL)u = 12(uR - uL)
No probabilistic interpretation in the helicity base (off diagonal)
Probabilistic interpretation in helicity base
q(x) spin averaged
(well known)
q(x) helicity diff(known)
q(x) helicity flip(unknown)
12 12
R R
12 12
L L
-12 12
R R
g1(x)
Transversitybase
12 -12
R L
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 7
- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different Q2 evolution than q - Sensitive to valence quark polarization
TransversityTransversity
Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner
PropertiesProperties
Impossible in DIS Direct Measurement
ppe+e-X epersquohX
Indirect MeasurementConvolution of with
unknown fragment fct
h1 x h1 h1 x Collins function
h1 must couple to another chiral-odd function
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 8
Elementary LO interaction
)( )()( )(1
9
42121
2
212
2
2
2
xqxqxqxqexxsMdxdM
d
F
2 22121 sQxsMxxxxx LFF
llqq
Drell-Yan processDrell-Yan process
dduuq
M invariant Massof lepton pair
sM 2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 9
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 10
h1 from pbar-p Drell-Yan at GSI
Similar predictions by Efremov et al
Eur Phys J C35 207 (2004)
PAX s=x1x2~01-03 rarr valence quarks (ATT large ~ 02-04 )
)()(
)()(ˆ
)()()()(
)()()()(ˆ
21
2111
21212
211121112
xuxu
xhxha
xqxqxqxqe
xhxhxhxheaA uu
TT
q q
q qqqqq
TTTT
Anselmino et al PLB 59497
(2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 11
Kinematics for Drell-Yan processes
QCD corrections might be very large at smaller values of M for cross-sections not for ATT K-factor almost
spin-independent H Shimizu G Sterman W Vogelsang and H Yokoya hep-ph0503270
V Barone et al in preparation
Fermilab E866 800 GeVc
CERN NA51 450 GeVc
safe region
JMM
s
M J 2
Usually taken as
Q2gt4 GeV2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 12
s=45 GeV2 s=210 GeV2
s=45 GeV2s=210 GeV2
Cross-section
Asymmetry
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 13
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 14
Single Spin Asymmetries (and their partonic
origin)
pq
Pq
π
kCollins effect = fragmentation of polarized quark
depends on Pqmiddot (pq x k)
P
pk
Sivers effect = number of partons in polarized
proton depends on P middot (p x k)
q
pk
Boer-Mulders effect = polarization of partons in
unpolarized proton depends on Pq middot (p x k)
qPq
Collins chiral-odd
Sivers chiral-even
Boer-Mulders chiral-odd
These effects may generate SSA
d d
d dNA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 15
BNL-AGS radics = 66 GeV 06 lt pT lt 12 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
STAR-RHIC radics = 200 GeV 11 lt pT lt 25 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
SSA pp rarr πX
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 16
SSA SIDIS
Collins Sivers HERMES
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 17
SSA SIDIS
COMPASS
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 18
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 2
PAX CollaborationPAX Collaboration
TIMELINE
Jan 04 Letter of Intent
May 04 QCD-PAC meeting at GSI
Aug 04 Workshop on polarized antiprotons at GSI
Jan 05 Technical Report
Mar 05 QCD-PAC meeting at GSI
178 physicists (121 in August 2004)35 institutions (15 EU 20 NON-EU)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 3
hellip the PAC would like to stress again the uniqueness of the program with polarized anti-protons and polarized protons that could become available at GSI
Evaluation by QCD-PAC (March Evaluation by QCD-PAC (March 2005)2005)
hellipthe PAC considers it is essential for the FAIR project to commit to polarized antiproton capability at this time and include polarized transport and acceleration capability in the HESR space for installation of the APR and CSR and associated hardware and the APR in the core project
We request the PAX collaboration to1) Commit to the construction and testing of the APR2) Explore all options to increase the luminosity to the value of 1031 cm-2s-
1
3) Prepare a more detailed physics proposal and detector design for each of the proposed stages These stages may include
a) 35 GeVc polarized antiprotons on a polarized proton targetb) 15 GeVc polarized antiprotons with the PANDA detector (for single spin asymmetries)c) 15 GeVc polarized antiprotons on a polarized proton target in a dedicated detector d) Collisions of 15 GeVc antiprotons with 35 GeVc polarized protons
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 4
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 5
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 6
Leading Twist Distribution Functions
12 12
L L
+f1(x)
h1(x)
proton
protonrsquo
quark
quarkrsquo
u = 12(uR + uL)u = 12(uR - uL)
No probabilistic interpretation in the helicity base (off diagonal)
Probabilistic interpretation in helicity base
q(x) spin averaged
(well known)
q(x) helicity diff(known)
q(x) helicity flip(unknown)
12 12
R R
12 12
L L
-12 12
R R
g1(x)
Transversitybase
12 -12
R L
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 7
- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different Q2 evolution than q - Sensitive to valence quark polarization
TransversityTransversity
Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner
PropertiesProperties
Impossible in DIS Direct Measurement
ppe+e-X epersquohX
Indirect MeasurementConvolution of with
unknown fragment fct
h1 x h1 h1 x Collins function
h1 must couple to another chiral-odd function
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 8
Elementary LO interaction
)( )()( )(1
9
42121
2
212
2
2
2
xqxqxqxqexxsMdxdM
d
F
2 22121 sQxsMxxxxx LFF
llqq
Drell-Yan processDrell-Yan process
dduuq
M invariant Massof lepton pair
sM 2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 9
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 10
h1 from pbar-p Drell-Yan at GSI
Similar predictions by Efremov et al
Eur Phys J C35 207 (2004)
PAX s=x1x2~01-03 rarr valence quarks (ATT large ~ 02-04 )
)()(
)()(ˆ
)()()()(
)()()()(ˆ
21
2111
21212
211121112
xuxu
xhxha
xqxqxqxqe
xhxhxhxheaA uu
TT
q q
q qqqqq
TTTT
Anselmino et al PLB 59497
(2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 11
Kinematics for Drell-Yan processes
QCD corrections might be very large at smaller values of M for cross-sections not for ATT K-factor almost
spin-independent H Shimizu G Sterman W Vogelsang and H Yokoya hep-ph0503270
V Barone et al in preparation
Fermilab E866 800 GeVc
CERN NA51 450 GeVc
safe region
JMM
s
M J 2
Usually taken as
Q2gt4 GeV2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 12
s=45 GeV2 s=210 GeV2
s=45 GeV2s=210 GeV2
Cross-section
Asymmetry
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 13
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 14
Single Spin Asymmetries (and their partonic
origin)
pq
Pq
π
kCollins effect = fragmentation of polarized quark
depends on Pqmiddot (pq x k)
P
pk
Sivers effect = number of partons in polarized
proton depends on P middot (p x k)
q
pk
Boer-Mulders effect = polarization of partons in
unpolarized proton depends on Pq middot (p x k)
qPq
Collins chiral-odd
Sivers chiral-even
Boer-Mulders chiral-odd
These effects may generate SSA
d d
d dNA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 15
BNL-AGS radics = 66 GeV 06 lt pT lt 12 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
STAR-RHIC radics = 200 GeV 11 lt pT lt 25 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
SSA pp rarr πX
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 16
SSA SIDIS
Collins Sivers HERMES
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 17
SSA SIDIS
COMPASS
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 18
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 3
hellip the PAC would like to stress again the uniqueness of the program with polarized anti-protons and polarized protons that could become available at GSI
Evaluation by QCD-PAC (March Evaluation by QCD-PAC (March 2005)2005)
hellipthe PAC considers it is essential for the FAIR project to commit to polarized antiproton capability at this time and include polarized transport and acceleration capability in the HESR space for installation of the APR and CSR and associated hardware and the APR in the core project
We request the PAX collaboration to1) Commit to the construction and testing of the APR2) Explore all options to increase the luminosity to the value of 1031 cm-2s-
1
3) Prepare a more detailed physics proposal and detector design for each of the proposed stages These stages may include
a) 35 GeVc polarized antiprotons on a polarized proton targetb) 15 GeVc polarized antiprotons with the PANDA detector (for single spin asymmetries)c) 15 GeVc polarized antiprotons on a polarized proton target in a dedicated detector d) Collisions of 15 GeVc antiprotons with 35 GeVc polarized protons
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 4
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 5
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 6
Leading Twist Distribution Functions
12 12
L L
+f1(x)
h1(x)
proton
protonrsquo
quark
quarkrsquo
u = 12(uR + uL)u = 12(uR - uL)
No probabilistic interpretation in the helicity base (off diagonal)
Probabilistic interpretation in helicity base
q(x) spin averaged
(well known)
q(x) helicity diff(known)
q(x) helicity flip(unknown)
12 12
R R
12 12
L L
-12 12
R R
g1(x)
Transversitybase
12 -12
R L
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 7
- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different Q2 evolution than q - Sensitive to valence quark polarization
TransversityTransversity
Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner
PropertiesProperties
Impossible in DIS Direct Measurement
ppe+e-X epersquohX
Indirect MeasurementConvolution of with
unknown fragment fct
h1 x h1 h1 x Collins function
h1 must couple to another chiral-odd function
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 8
Elementary LO interaction
)( )()( )(1
9
42121
2
212
2
2
2
xqxqxqxqexxsMdxdM
d
F
2 22121 sQxsMxxxxx LFF
llqq
Drell-Yan processDrell-Yan process
dduuq
M invariant Massof lepton pair
sM 2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 9
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 10
h1 from pbar-p Drell-Yan at GSI
Similar predictions by Efremov et al
Eur Phys J C35 207 (2004)
PAX s=x1x2~01-03 rarr valence quarks (ATT large ~ 02-04 )
)()(
)()(ˆ
)()()()(
)()()()(ˆ
21
2111
21212
211121112
xuxu
xhxha
xqxqxqxqe
xhxhxhxheaA uu
TT
q q
q qqqqq
TTTT
Anselmino et al PLB 59497
(2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 11
Kinematics for Drell-Yan processes
QCD corrections might be very large at smaller values of M for cross-sections not for ATT K-factor almost
spin-independent H Shimizu G Sterman W Vogelsang and H Yokoya hep-ph0503270
V Barone et al in preparation
Fermilab E866 800 GeVc
CERN NA51 450 GeVc
safe region
JMM
s
M J 2
Usually taken as
Q2gt4 GeV2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 12
s=45 GeV2 s=210 GeV2
s=45 GeV2s=210 GeV2
Cross-section
Asymmetry
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 13
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 14
Single Spin Asymmetries (and their partonic
origin)
pq
Pq
π
kCollins effect = fragmentation of polarized quark
depends on Pqmiddot (pq x k)
P
pk
Sivers effect = number of partons in polarized
proton depends on P middot (p x k)
q
pk
Boer-Mulders effect = polarization of partons in
unpolarized proton depends on Pq middot (p x k)
qPq
Collins chiral-odd
Sivers chiral-even
Boer-Mulders chiral-odd
These effects may generate SSA
d d
d dNA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 15
BNL-AGS radics = 66 GeV 06 lt pT lt 12 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
STAR-RHIC radics = 200 GeV 11 lt pT lt 25 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
SSA pp rarr πX
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 16
SSA SIDIS
Collins Sivers HERMES
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 17
SSA SIDIS
COMPASS
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 18
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 4
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 5
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 6
Leading Twist Distribution Functions
12 12
L L
+f1(x)
h1(x)
proton
protonrsquo
quark
quarkrsquo
u = 12(uR + uL)u = 12(uR - uL)
No probabilistic interpretation in the helicity base (off diagonal)
Probabilistic interpretation in helicity base
q(x) spin averaged
(well known)
q(x) helicity diff(known)
q(x) helicity flip(unknown)
12 12
R R
12 12
L L
-12 12
R R
g1(x)
Transversitybase
12 -12
R L
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 7
- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different Q2 evolution than q - Sensitive to valence quark polarization
TransversityTransversity
Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner
PropertiesProperties
Impossible in DIS Direct Measurement
ppe+e-X epersquohX
Indirect MeasurementConvolution of with
unknown fragment fct
h1 x h1 h1 x Collins function
h1 must couple to another chiral-odd function
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 8
Elementary LO interaction
)( )()( )(1
9
42121
2
212
2
2
2
xqxqxqxqexxsMdxdM
d
F
2 22121 sQxsMxxxxx LFF
llqq
Drell-Yan processDrell-Yan process
dduuq
M invariant Massof lepton pair
sM 2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 9
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 10
h1 from pbar-p Drell-Yan at GSI
Similar predictions by Efremov et al
Eur Phys J C35 207 (2004)
PAX s=x1x2~01-03 rarr valence quarks (ATT large ~ 02-04 )
)()(
)()(ˆ
)()()()(
)()()()(ˆ
21
2111
21212
211121112
xuxu
xhxha
xqxqxqxqe
xhxhxhxheaA uu
TT
q q
q qqqqq
TTTT
Anselmino et al PLB 59497
(2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 11
Kinematics for Drell-Yan processes
QCD corrections might be very large at smaller values of M for cross-sections not for ATT K-factor almost
spin-independent H Shimizu G Sterman W Vogelsang and H Yokoya hep-ph0503270
V Barone et al in preparation
Fermilab E866 800 GeVc
CERN NA51 450 GeVc
safe region
JMM
s
M J 2
Usually taken as
Q2gt4 GeV2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 12
s=45 GeV2 s=210 GeV2
s=45 GeV2s=210 GeV2
Cross-section
Asymmetry
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 13
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 14
Single Spin Asymmetries (and their partonic
origin)
pq
Pq
π
kCollins effect = fragmentation of polarized quark
depends on Pqmiddot (pq x k)
P
pk
Sivers effect = number of partons in polarized
proton depends on P middot (p x k)
q
pk
Boer-Mulders effect = polarization of partons in
unpolarized proton depends on Pq middot (p x k)
qPq
Collins chiral-odd
Sivers chiral-even
Boer-Mulders chiral-odd
These effects may generate SSA
d d
d dNA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 15
BNL-AGS radics = 66 GeV 06 lt pT lt 12 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
STAR-RHIC radics = 200 GeV 11 lt pT lt 25 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
SSA pp rarr πX
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 16
SSA SIDIS
Collins Sivers HERMES
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 17
SSA SIDIS
COMPASS
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 18
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 5
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 6
Leading Twist Distribution Functions
12 12
L L
+f1(x)
h1(x)
proton
protonrsquo
quark
quarkrsquo
u = 12(uR + uL)u = 12(uR - uL)
No probabilistic interpretation in the helicity base (off diagonal)
Probabilistic interpretation in helicity base
q(x) spin averaged
(well known)
q(x) helicity diff(known)
q(x) helicity flip(unknown)
12 12
R R
12 12
L L
-12 12
R R
g1(x)
Transversitybase
12 -12
R L
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 7
- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different Q2 evolution than q - Sensitive to valence quark polarization
TransversityTransversity
Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner
PropertiesProperties
Impossible in DIS Direct Measurement
ppe+e-X epersquohX
Indirect MeasurementConvolution of with
unknown fragment fct
h1 x h1 h1 x Collins function
h1 must couple to another chiral-odd function
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 8
Elementary LO interaction
)( )()( )(1
9
42121
2
212
2
2
2
xqxqxqxqexxsMdxdM
d
F
2 22121 sQxsMxxxxx LFF
llqq
Drell-Yan processDrell-Yan process
dduuq
M invariant Massof lepton pair
sM 2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 9
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 10
h1 from pbar-p Drell-Yan at GSI
Similar predictions by Efremov et al
Eur Phys J C35 207 (2004)
PAX s=x1x2~01-03 rarr valence quarks (ATT large ~ 02-04 )
)()(
)()(ˆ
)()()()(
)()()()(ˆ
21
2111
21212
211121112
xuxu
xhxha
xqxqxqxqe
xhxhxhxheaA uu
TT
q q
q qqqqq
TTTT
Anselmino et al PLB 59497
(2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 11
Kinematics for Drell-Yan processes
QCD corrections might be very large at smaller values of M for cross-sections not for ATT K-factor almost
spin-independent H Shimizu G Sterman W Vogelsang and H Yokoya hep-ph0503270
V Barone et al in preparation
Fermilab E866 800 GeVc
CERN NA51 450 GeVc
safe region
JMM
s
M J 2
Usually taken as
Q2gt4 GeV2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 12
s=45 GeV2 s=210 GeV2
s=45 GeV2s=210 GeV2
Cross-section
Asymmetry
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 13
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 14
Single Spin Asymmetries (and their partonic
origin)
pq
Pq
π
kCollins effect = fragmentation of polarized quark
depends on Pqmiddot (pq x k)
P
pk
Sivers effect = number of partons in polarized
proton depends on P middot (p x k)
q
pk
Boer-Mulders effect = polarization of partons in
unpolarized proton depends on Pq middot (p x k)
qPq
Collins chiral-odd
Sivers chiral-even
Boer-Mulders chiral-odd
These effects may generate SSA
d d
d dNA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 15
BNL-AGS radics = 66 GeV 06 lt pT lt 12 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
STAR-RHIC radics = 200 GeV 11 lt pT lt 25 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
SSA pp rarr πX
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 16
SSA SIDIS
Collins Sivers HERMES
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 17
SSA SIDIS
COMPASS
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 18
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 6
Leading Twist Distribution Functions
12 12
L L
+f1(x)
h1(x)
proton
protonrsquo
quark
quarkrsquo
u = 12(uR + uL)u = 12(uR - uL)
No probabilistic interpretation in the helicity base (off diagonal)
Probabilistic interpretation in helicity base
q(x) spin averaged
(well known)
q(x) helicity diff(known)
q(x) helicity flip(unknown)
12 12
R R
12 12
L L
-12 12
R R
g1(x)
Transversitybase
12 -12
R L
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 7
- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different Q2 evolution than q - Sensitive to valence quark polarization
TransversityTransversity
Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner
PropertiesProperties
Impossible in DIS Direct Measurement
ppe+e-X epersquohX
Indirect MeasurementConvolution of with
unknown fragment fct
h1 x h1 h1 x Collins function
h1 must couple to another chiral-odd function
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 8
Elementary LO interaction
)( )()( )(1
9
42121
2
212
2
2
2
xqxqxqxqexxsMdxdM
d
F
2 22121 sQxsMxxxxx LFF
llqq
Drell-Yan processDrell-Yan process
dduuq
M invariant Massof lepton pair
sM 2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 9
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 10
h1 from pbar-p Drell-Yan at GSI
Similar predictions by Efremov et al
Eur Phys J C35 207 (2004)
PAX s=x1x2~01-03 rarr valence quarks (ATT large ~ 02-04 )
)()(
)()(ˆ
)()()()(
)()()()(ˆ
21
2111
21212
211121112
xuxu
xhxha
xqxqxqxqe
xhxhxhxheaA uu
TT
q q
q qqqqq
TTTT
Anselmino et al PLB 59497
(2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 11
Kinematics for Drell-Yan processes
QCD corrections might be very large at smaller values of M for cross-sections not for ATT K-factor almost
spin-independent H Shimizu G Sterman W Vogelsang and H Yokoya hep-ph0503270
V Barone et al in preparation
Fermilab E866 800 GeVc
CERN NA51 450 GeVc
safe region
JMM
s
M J 2
Usually taken as
Q2gt4 GeV2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 12
s=45 GeV2 s=210 GeV2
s=45 GeV2s=210 GeV2
Cross-section
Asymmetry
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 13
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 14
Single Spin Asymmetries (and their partonic
origin)
pq
Pq
π
kCollins effect = fragmentation of polarized quark
depends on Pqmiddot (pq x k)
P
pk
Sivers effect = number of partons in polarized
proton depends on P middot (p x k)
q
pk
Boer-Mulders effect = polarization of partons in
unpolarized proton depends on Pq middot (p x k)
qPq
Collins chiral-odd
Sivers chiral-even
Boer-Mulders chiral-odd
These effects may generate SSA
d d
d dNA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 15
BNL-AGS radics = 66 GeV 06 lt pT lt 12 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
STAR-RHIC radics = 200 GeV 11 lt pT lt 25 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
SSA pp rarr πX
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 16
SSA SIDIS
Collins Sivers HERMES
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 17
SSA SIDIS
COMPASS
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 18
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 7
- Probes relativistic nature of quarks- No gluon analog for spin-12 nucleon- Different Q2 evolution than q - Sensitive to valence quark polarization
TransversityTransversity
Chiral-odd requires another chiral-odd partnerChiral-odd requires another chiral-odd partner
PropertiesProperties
Impossible in DIS Direct Measurement
ppe+e-X epersquohX
Indirect MeasurementConvolution of with
unknown fragment fct
h1 x h1 h1 x Collins function
h1 must couple to another chiral-odd function
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 8
Elementary LO interaction
)( )()( )(1
9
42121
2
212
2
2
2
xqxqxqxqexxsMdxdM
d
F
2 22121 sQxsMxxxxx LFF
llqq
Drell-Yan processDrell-Yan process
dduuq
M invariant Massof lepton pair
sM 2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 9
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 10
h1 from pbar-p Drell-Yan at GSI
Similar predictions by Efremov et al
Eur Phys J C35 207 (2004)
PAX s=x1x2~01-03 rarr valence quarks (ATT large ~ 02-04 )
)()(
)()(ˆ
)()()()(
)()()()(ˆ
21
2111
21212
211121112
xuxu
xhxha
xqxqxqxqe
xhxhxhxheaA uu
TT
q q
q qqqqq
TTTT
Anselmino et al PLB 59497
(2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 11
Kinematics for Drell-Yan processes
QCD corrections might be very large at smaller values of M for cross-sections not for ATT K-factor almost
spin-independent H Shimizu G Sterman W Vogelsang and H Yokoya hep-ph0503270
V Barone et al in preparation
Fermilab E866 800 GeVc
CERN NA51 450 GeVc
safe region
JMM
s
M J 2
Usually taken as
Q2gt4 GeV2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 12
s=45 GeV2 s=210 GeV2
s=45 GeV2s=210 GeV2
Cross-section
Asymmetry
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 13
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 14
Single Spin Asymmetries (and their partonic
origin)
pq
Pq
π
kCollins effect = fragmentation of polarized quark
depends on Pqmiddot (pq x k)
P
pk
Sivers effect = number of partons in polarized
proton depends on P middot (p x k)
q
pk
Boer-Mulders effect = polarization of partons in
unpolarized proton depends on Pq middot (p x k)
qPq
Collins chiral-odd
Sivers chiral-even
Boer-Mulders chiral-odd
These effects may generate SSA
d d
d dNA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 15
BNL-AGS radics = 66 GeV 06 lt pT lt 12 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
STAR-RHIC radics = 200 GeV 11 lt pT lt 25 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
SSA pp rarr πX
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 16
SSA SIDIS
Collins Sivers HERMES
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 17
SSA SIDIS
COMPASS
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 18
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 8
Elementary LO interaction
)( )()( )(1
9
42121
2
212
2
2
2
xqxqxqxqexxsMdxdM
d
F
2 22121 sQxsMxxxxx LFF
llqq
Drell-Yan processDrell-Yan process
dduuq
M invariant Massof lepton pair
sM 2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 9
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 10
h1 from pbar-p Drell-Yan at GSI
Similar predictions by Efremov et al
Eur Phys J C35 207 (2004)
PAX s=x1x2~01-03 rarr valence quarks (ATT large ~ 02-04 )
)()(
)()(ˆ
)()()()(
)()()()(ˆ
21
2111
21212
211121112
xuxu
xhxha
xqxqxqxqe
xhxhxhxheaA uu
TT
q q
q qqqqq
TTTT
Anselmino et al PLB 59497
(2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 11
Kinematics for Drell-Yan processes
QCD corrections might be very large at smaller values of M for cross-sections not for ATT K-factor almost
spin-independent H Shimizu G Sterman W Vogelsang and H Yokoya hep-ph0503270
V Barone et al in preparation
Fermilab E866 800 GeVc
CERN NA51 450 GeVc
safe region
JMM
s
M J 2
Usually taken as
Q2gt4 GeV2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 12
s=45 GeV2 s=210 GeV2
s=45 GeV2s=210 GeV2
Cross-section
Asymmetry
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 13
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 14
Single Spin Asymmetries (and their partonic
origin)
pq
Pq
π
kCollins effect = fragmentation of polarized quark
depends on Pqmiddot (pq x k)
P
pk
Sivers effect = number of partons in polarized
proton depends on P middot (p x k)
q
pk
Boer-Mulders effect = polarization of partons in
unpolarized proton depends on Pq middot (p x k)
qPq
Collins chiral-odd
Sivers chiral-even
Boer-Mulders chiral-odd
These effects may generate SSA
d d
d dNA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 15
BNL-AGS radics = 66 GeV 06 lt pT lt 12 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
STAR-RHIC radics = 200 GeV 11 lt pT lt 25 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
SSA pp rarr πX
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 16
SSA SIDIS
Collins Sivers HERMES
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 17
SSA SIDIS
COMPASS
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 18
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 9
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 10
h1 from pbar-p Drell-Yan at GSI
Similar predictions by Efremov et al
Eur Phys J C35 207 (2004)
PAX s=x1x2~01-03 rarr valence quarks (ATT large ~ 02-04 )
)()(
)()(ˆ
)()()()(
)()()()(ˆ
21
2111
21212
211121112
xuxu
xhxha
xqxqxqxqe
xhxhxhxheaA uu
TT
q q
q qqqqq
TTTT
Anselmino et al PLB 59497
(2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 11
Kinematics for Drell-Yan processes
QCD corrections might be very large at smaller values of M for cross-sections not for ATT K-factor almost
spin-independent H Shimizu G Sterman W Vogelsang and H Yokoya hep-ph0503270
V Barone et al in preparation
Fermilab E866 800 GeVc
CERN NA51 450 GeVc
safe region
JMM
s
M J 2
Usually taken as
Q2gt4 GeV2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 12
s=45 GeV2 s=210 GeV2
s=45 GeV2s=210 GeV2
Cross-section
Asymmetry
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 13
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 14
Single Spin Asymmetries (and their partonic
origin)
pq
Pq
π
kCollins effect = fragmentation of polarized quark
depends on Pqmiddot (pq x k)
P
pk
Sivers effect = number of partons in polarized
proton depends on P middot (p x k)
q
pk
Boer-Mulders effect = polarization of partons in
unpolarized proton depends on Pq middot (p x k)
qPq
Collins chiral-odd
Sivers chiral-even
Boer-Mulders chiral-odd
These effects may generate SSA
d d
d dNA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 15
BNL-AGS radics = 66 GeV 06 lt pT lt 12 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
STAR-RHIC radics = 200 GeV 11 lt pT lt 25 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
SSA pp rarr πX
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 16
SSA SIDIS
Collins Sivers HERMES
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 17
SSA SIDIS
COMPASS
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 18
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 10
h1 from pbar-p Drell-Yan at GSI
Similar predictions by Efremov et al
Eur Phys J C35 207 (2004)
PAX s=x1x2~01-03 rarr valence quarks (ATT large ~ 02-04 )
)()(
)()(ˆ
)()()()(
)()()()(ˆ
21
2111
21212
211121112
xuxu
xhxha
xqxqxqxqe
xhxhxhxheaA uu
TT
q q
q qqqqq
TTTT
Anselmino et al PLB 59497
(2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 11
Kinematics for Drell-Yan processes
QCD corrections might be very large at smaller values of M for cross-sections not for ATT K-factor almost
spin-independent H Shimizu G Sterman W Vogelsang and H Yokoya hep-ph0503270
V Barone et al in preparation
Fermilab E866 800 GeVc
CERN NA51 450 GeVc
safe region
JMM
s
M J 2
Usually taken as
Q2gt4 GeV2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 12
s=45 GeV2 s=210 GeV2
s=45 GeV2s=210 GeV2
Cross-section
Asymmetry
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 13
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 14
Single Spin Asymmetries (and their partonic
origin)
pq
Pq
π
kCollins effect = fragmentation of polarized quark
depends on Pqmiddot (pq x k)
P
pk
Sivers effect = number of partons in polarized
proton depends on P middot (p x k)
q
pk
Boer-Mulders effect = polarization of partons in
unpolarized proton depends on Pq middot (p x k)
qPq
Collins chiral-odd
Sivers chiral-even
Boer-Mulders chiral-odd
These effects may generate SSA
d d
d dNA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 15
BNL-AGS radics = 66 GeV 06 lt pT lt 12 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
STAR-RHIC radics = 200 GeV 11 lt pT lt 25 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
SSA pp rarr πX
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 16
SSA SIDIS
Collins Sivers HERMES
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 17
SSA SIDIS
COMPASS
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 18
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 11
Kinematics for Drell-Yan processes
QCD corrections might be very large at smaller values of M for cross-sections not for ATT K-factor almost
spin-independent H Shimizu G Sterman W Vogelsang and H Yokoya hep-ph0503270
V Barone et al in preparation
Fermilab E866 800 GeVc
CERN NA51 450 GeVc
safe region
JMM
s
M J 2
Usually taken as
Q2gt4 GeV2
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 12
s=45 GeV2 s=210 GeV2
s=45 GeV2s=210 GeV2
Cross-section
Asymmetry
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 13
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 14
Single Spin Asymmetries (and their partonic
origin)
pq
Pq
π
kCollins effect = fragmentation of polarized quark
depends on Pqmiddot (pq x k)
P
pk
Sivers effect = number of partons in polarized
proton depends on P middot (p x k)
q
pk
Boer-Mulders effect = polarization of partons in
unpolarized proton depends on Pq middot (p x k)
qPq
Collins chiral-odd
Sivers chiral-even
Boer-Mulders chiral-odd
These effects may generate SSA
d d
d dNA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 15
BNL-AGS radics = 66 GeV 06 lt pT lt 12 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
STAR-RHIC radics = 200 GeV 11 lt pT lt 25 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
SSA pp rarr πX
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 16
SSA SIDIS
Collins Sivers HERMES
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 17
SSA SIDIS
COMPASS
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 18
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 12
s=45 GeV2 s=210 GeV2
s=45 GeV2s=210 GeV2
Cross-section
Asymmetry
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 13
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 14
Single Spin Asymmetries (and their partonic
origin)
pq
Pq
π
kCollins effect = fragmentation of polarized quark
depends on Pqmiddot (pq x k)
P
pk
Sivers effect = number of partons in polarized
proton depends on P middot (p x k)
q
pk
Boer-Mulders effect = polarization of partons in
unpolarized proton depends on Pq middot (p x k)
qPq
Collins chiral-odd
Sivers chiral-even
Boer-Mulders chiral-odd
These effects may generate SSA
d d
d dNA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 15
BNL-AGS radics = 66 GeV 06 lt pT lt 12 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
STAR-RHIC radics = 200 GeV 11 lt pT lt 25 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
SSA pp rarr πX
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 16
SSA SIDIS
Collins Sivers HERMES
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 17
SSA SIDIS
COMPASS
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 18
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 13
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 14
Single Spin Asymmetries (and their partonic
origin)
pq
Pq
π
kCollins effect = fragmentation of polarized quark
depends on Pqmiddot (pq x k)
P
pk
Sivers effect = number of partons in polarized
proton depends on P middot (p x k)
q
pk
Boer-Mulders effect = polarization of partons in
unpolarized proton depends on Pq middot (p x k)
qPq
Collins chiral-odd
Sivers chiral-even
Boer-Mulders chiral-odd
These effects may generate SSA
d d
d dNA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 15
BNL-AGS radics = 66 GeV 06 lt pT lt 12 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
STAR-RHIC radics = 200 GeV 11 lt pT lt 25 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
SSA pp rarr πX
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 16
SSA SIDIS
Collins Sivers HERMES
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 17
SSA SIDIS
COMPASS
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 18
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 14
Single Spin Asymmetries (and their partonic
origin)
pq
Pq
π
kCollins effect = fragmentation of polarized quark
depends on Pqmiddot (pq x k)
P
pk
Sivers effect = number of partons in polarized
proton depends on P middot (p x k)
q
pk
Boer-Mulders effect = polarization of partons in
unpolarized proton depends on Pq middot (p x k)
qPq
Collins chiral-odd
Sivers chiral-even
Boer-Mulders chiral-odd
These effects may generate SSA
d d
d dNA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 15
BNL-AGS radics = 66 GeV 06 lt pT lt 12 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
STAR-RHIC radics = 200 GeV 11 lt pT lt 25 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
SSA pp rarr πX
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 16
SSA SIDIS
Collins Sivers HERMES
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 17
SSA SIDIS
COMPASS
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 18
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 15
BNL-AGS radics = 66 GeV 06 lt pT lt 12 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
STAR-RHIC radics = 200 GeV 11 lt pT lt 25 puarrp
E704 radics = 20 GeV 07 lt pT lt 20 puarrp
SSA pp rarr πX
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 16
SSA SIDIS
Collins Sivers HERMES
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 17
SSA SIDIS
COMPASS
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 18
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 16
SSA SIDIS
Collins Sivers HERMES
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 17
SSA SIDIS
COMPASS
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 18
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 17
SSA SIDIS
COMPASS
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 18
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 18
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 19
pp Elastic Scattering from ZGSpp Elastic Scattering from ZGS
Spin-dependence at large-PSpin-dependence at large-P (90deg90degcmcm))
Hard scattering takes Hard scattering takes place only with spins place only with spins
DG Crabb et al PRL 41 1257 (1978)
T=1085 GeV
Similar studies in pp elastic scattering
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 20
Physics with polarized antiprotons at GSI-PAX
Transversity via Drell-Yan processes
TTA direct access to transversity
Transverse Single Spin Asymmetries
QCD ldquotheoremrdquo (Sivers)D-Y = ndash (Sivers)DISNA
Time-like elm form factors
llpp form factors
Elastic processes
SLSSLLNNN AAA AA spin mysteries like in pp
High Energy
Low Energy
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 21
(Phys RevC 68 (2003) 034325)
JLab PT data
SLAC RS data
TWO DIFFERENTS METHODS
TWO DIFFERENTS RESULTS
COMPARISON BETWEEN
ROSENBLUTH SEPARATION AND
POLARIZATION TRANSFER TECNIQUES
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 22
Proton Electromagnetic Proton Electromagnetic Formfactors Formfactors
bull Single-spin asymmetry in pp rarr e+e-
ndash Measurement of relative phases of magnetic and electric FF in the time-like region
bull Double-spin asymmetry in pp rarr e+e-
ndash independent GE-Gm separation
ndash test of Rosenbluth separation in the time-like region
2
p2
2E
22M
2M
E
y
m4q
|G|)(sin|G|)(cos1
)GGIm()2sin(A
S Brodsky et al Phys Rev D69 (2004)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 23
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 24
Facilty for Antiproton and Ion Research (GSI Darmstadt Germany)
-Proton linac (injector)-2 synchrotons (30 GeV p)-A number of storage rings Parallel beams operation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 25
HESR
Antiproton Production
Target
HESR (High Energy Storage Ring) p = 15 - 15 GeVc (22 GeVc) (Length 442 m Bρ = 50 Tm)
PANDA storage ring (N=5 x 1010
pbar)
High luminosity mode (Δpp ~ 10-4) Luminosity = 2 x 1032 cm-2s-1
High resolution mode (Δpp ~ 10-5 ) Luminosity = 1031 cm-2s-1
PAX synchroton (N=3 x 1011 pbar) Preserve polarization Luminosity = 2 x 1030 cm-2s-1
The Antiproton FacilityThe Antiproton Facility
bullAntiproton production similar to CERN
bullProduction rate 107sec at 30 GeV
SuperFRS
NESR
CR
Beam Cooling e- andor stochastic
SIS100300
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 26
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 27
PAX Accelerator SetupPAX Accelerator Setup
In the following focus on two issuesbull Antiproton Polarizer Ring (APR)bull Asymmetric Antiproton-Proton Collider
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 28
Staging Staging Phase I (PAXCSR)Phase I (PAXCSR)
Physics EMFFpbar-p elastic
Experiment polunpol pbar on internal polarized target
Independent from HESR running
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 29
Staging Staging Phase II (PAXHESR)Phase II (PAXHESR)
EXPERIMENT1 Asymmetric collider polarized antiprotons in HESR (p=15 GeVc)
polarized protons in CSR (p=35 GeVc)2 Internal polarized target with 22 GeVc polarized antiproton
beam
Physics Transversity
Second IP with minor interference with PANDA
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 30
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 31
Principle of spin filter methodPrinciple of spin filter method
P beam polarizationQ target polarizationk || beam direction
σtot = σ0 + σmiddotPmiddotQ + σ||middot(Pmiddotk)(Qmiddotk)
transverse case
Q0tot
longitudinal case
Q)( ||0tot
For initially equally populated spin states (m=+frac12) and (m=-frac12)
Unpolarized anti-p beam
Polarized H target
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 32
The HERMES targetThe HERMES target
Atomic Beam SourceNIM A 505 (2003) 633
Pz+ = |1gt + |4gt
Pz- = |2gt + |3gt
mmjj = = ++1212
mmjj = = --1212
mmii=-12=-12
mmii=-12=-12
mmii=+1=+122
mmii=+1=+122
1|1gt|2gt
|3gt|4gt
ee-
pp|1gt
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 33
Performance of Polarized Internal Performance of Polarized Internal TargetsTargets
PT = 0795 0033
HERMES
H Transverse Field (B=297 mT)
HERMES
Dz
Dzz
PT = 0845 plusmn 0028
Longitudinal Field (B=335 mT)
HERMES Stored Positrons PINTEX Stored Protons
H
Fast reorientation in a weak field (xyz)
Targets work very reliably (months of stable operation)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 34
Exploitation of Spin TransferExploitation of Spin Transfer
PAX will employ spin-filter from internal polarized hydrogen
target to antiprotons
Hydrogen gas target in strong field (300 mT)
F Rathmann et al PRL 71 1379 (1993)
Low energy pp scattering 1lt0 tot+lttot-
Expectation
Target Beam
FILTEX ResultsFILTEX Results
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 35
Puzzle from FILTEX TestPuzzle from FILTEX TestObserved polarization build-up dPdt = plusmn (124 plusmn 006) x 10-2 h-1
Expected build-up P(t)=tanh(tτpol)
1τpol=σ1Qdtf=24x10-2 h-1
about factor 2 larger
σ1 = 122 mb (pp phase shifts)Q = 083 plusmn 003dt = (56 plusmn 03) x 1013cm-2
f = 1177 MHz
Three distinct effects (measured 1=69 mb)
1 Selective removal through scattering beyond Ψacc=44 mrad σR=83 mb
2 Small angle scattering of target protons into ring acceptance σS=52 mb
3 Spin transfer from polarized electrons of the target atoms to the stored protons
σEM=70 mb (-) Horowitz amp Meyer PRL 72 3981 (1994)
HO Meyer PRE 50 1485 (1994)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 36
01
02
03
04
Beam
Pola
riza
tion
P(2
middotτbeam)
10 T (MeV)100
EM only
5
10
30
20
40
Ψacc=50 mrad
0
1
Filter Test T = 23 MeV Ψacc= 44 mrad
Beam PolarizationBeam Polarization (Electromagnetic Interaction)(Electromagnetic Interaction)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 37
Beam Polarization Beam Polarization (Hadronic Interaction Longitudinal Case)(Hadronic Interaction Longitudinal Case)
Experimental Tests requiredbullEM effect needs protons only (COSY)bullFinal Design of APR Filter test with p at AD (CERN)
Model D V Mull K Holinde Phys Rev C 51 2360 (1995)
Model A T Hippchen et al Phys Rev C 44 1323 (1991)
50 100 150 200 250 T (MeV) 50 100 150 200 T (MeV)
005
010
015
020
P
005
010
015
020
P
2 beam lifetimesΨacc=10-50 mrad
3 beam lifetimesΨacc=20 mrad
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 38
SMILESMILE SSpin pin MMeasurements easurements
in in IInteractions at nteractions at LLow ow EEnergy nergy
bull Study of spin-filtering process
bull Electromagnetic interaction unpolarized protons on polarized internal target at COSY
bull Hadronic interaction unpolarized antiprotons on polarized internal target at AD (CERN)
From COSY to FAIRhellipFrom COSY to FAIRhellip
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 39
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 40
RINGS SETUP RINGS SETUP
asymmetric collider L = 2∙1030 cm-2s-1
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 41
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 42
PAX Detector Concept PAX Detector Concept
Physics h1 distribution sin2 EMFF sin2
pbar-p elastic high |t|
Magnet Keeps beam polarization vertical Compatible with Cerenkov Compatible with polarized target
Detector Extremely rare DY signal (10-7 p-pbar) Maximum Bjorken-x coverage (M interval) Excellent PID (hadrone rejection ~ 104) High mass resolution (le2 )
Moderate lepton energies (05-5 GeV)
Azimuthally SymmetricBARREL GEOMETRY
LARGE ANGLES
Experiment Flexible Facility
TOROIDNO FRINGE FIELD
e+e-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 43
PAX Detector Concept PAX Detector Concept
Designed for Collider but compatible with fixed target
Cerenkov(200 m)
(20 m)
GEANT simulation
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 44
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 45
-p Phase Space-p Phase Space
Background peaks at low energy forward direction
acceptance
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 46
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 47
-p Phase Space-p Phase Space
Vertex resolution high enoughto study charm background
Better than 2 mass resol x dependence of h1
resonance vs continuum
Mandatory to study M below Jψ mass
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 48
OutlineOutlinebull Introduction
ndash Physics Casendash The FAIR project
bull PAX Accelerator Setupndash Stagingndash Antiproton Polarizer Ringndash Asymmetric Antiproton-Proton Collider
bull Experimentndash Conceptual Detector Designndash Preliminary Results for Drell-Yan Studiesndash Rate estimates
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 49
10 precision on the h1u (x) in the valence region
1 year of data taking at 15+35 GeV collider L = 2∙1030 cm-2s-1
Precision in hPrecision in h11 measurement measurement
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 50
Summary
bull PAX project has an innovative spin physics program transversity SSA EMFF hard p-pbar scatterings
bull A method to obtain an antiproton beam with high degree of polarization has to be optimized (APR)
bull PAX viable accelerator setup provides fexible 2nd IP really matched to the physics items lots of interesting QCD physics in PAX Phase-I asymmetric collider ideal to map transversity (Phase-II)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 51
Background to Drell-Yan eBackground to Drell-Yan e++ee--
frac12 hour experiment 2∙108 p-pbar interactions several DY events
combinatorial+charm bckg
Background 11 to signal after PID Egt300 MeV conversion veto mass cut the combinatorial component can be subtracted (wrong-sign control sample) the charm can be reduced (vertex decay)
+-++ amp --
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 52
PAX Integrated Luminosities for Physics PAX Integrated Luminosities for Physics CasesCases
pb-1
fb-1
Inte
gra
ted
Lu
min
osi
ty
EMFF DSA s=376 GeV2
ppbar elastic DSA t=4 GeV2
Phase-I L=151031 cm-2s-1
Antiproton Beam Polarization Ppbar=03 Proton Polarization Pp=08
Phase-II L=21030 cm-2s-1
EMFF DSA s=9 GeV2
Absolute Error ΔDSA=005
h1 DSA Mgt2 GeV Δ=10
h1 DSA Mgt4 GeV Δ=20
(1 y)
(4 y)(1 y)
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-
Spin Workshop 05 Dubna M Contalbrigo - INFN Ferrara 53
q q
q qqqqq
TTTT xqxqxqxqe
xhxhxhxheaA
)()()()(
)()()()(ˆ
dd
dd
21212
211121112
Barone Calarco Drago
Martin Schaumlfer Stratmann Vogelsang
h1 from p-p Drell-Yan at RICHU70
h1q (x Q2) small and with much slower evolution than
Δq(x Q2) and q(x Q2) at small x
h1q (x Q2)- h1q (x Q2)ne
RHIC τ=x1x2~10-3 rarr sea quarks (ATT very small ~ 001 )
3102 RICH energies 22 GeV 100 GeV 200 Ms
- PAX Polarized Antiproton eXperiments
- PAX Collaboration
- Slide 3
- Outline
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- pp Elastic Scattering from ZGS
- Slide 20
- Proton Electromagnetic Formfactors
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- PAX Accelerator Setup
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- SMILE Spin Measurements in Interactions at Low Energy
- Slide 39
- Slide 40
- Slide 41
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- Slide 46
- Slide 47
- Slide 48
- Slide 49
- Summary
- Slide 51
- PAX Integrated Luminosities for Physics Cases
- Slide 53
-