Fermilab Nov. 30, 2005 Włodek Guryn Results from the PP2PP Experiment at RHIC and Future Plans...

FermilabNov. 30, 2005

Włodek Guryn

Results from the PP2PP Experiment at RHIC and Future Plans Włodek Guryn

Brookhaven National Laboratory, Upton, NY, USA

OUTLINE of the TALK

•Description of the experiment

•Description of analysis

•Results and interpretation

•Future plans with STAR


Włodek Guryn

The Relativistic Heavy Ion Collider

RHIC is a QCD Laboratory:Nucleus- Nucleus collisions (AuAu, CuCu…); Asym. Nucl. (dAu);

Polarized proton-proton; eRHIC - Future


Włodek Guryn

RHIC pp accelerator complex

BRAHMS & PP2PP

STARPHENIX

AGS

LINACBOOSTER

Pol. Proton Source

Spin Rotators

20% Snake

Siberian Snakes

200 MeV polarimeter

AGS quasi-elastic polarimeter

Rf Dipoles

RHIC pC “CNI” polarimeters

PHOBOS

RHIC

absolute pHpolarimeter

SiberianSnakes

AGS pC “CNI” polarimeter

5% Snake


Włodek Guryn

Total and Differential Cross Sections, and Polarization Effects in pp Elastic Scattering at RHIC

S. Bültmann, I. H. Chiang, R.E. Chrien, A. Drees, R. Gill, W. Guryn*, J. Landgraf, T.A. Ljubičič, D. Lynn, C. Pearson, P. Pile, A. Rusek, M. Sakitt, S. Tepikian, K. Yip

Brookhaven National Laboratory, USA

J. Chwastowski, B. PawlikInstitute of Nuclear Physics, Cracow, Poland

M. HaguenauerEcole Polytechnique/IN2P3-CNRS, Palaiseau, France

A. A. Bogdanov, S.B. Nurushev, M.F Runtzo, M. N. StrikhanovMoscow Engineering Physics Institute (MEPHI), Moscow, Russia

I. G. Alekseev, V. P. Kanavets, L. I. Koroleva, B. V. Morozov, D. N. SviridaITEP, Moscow, Russia

S. Khodinov, M. Rijssenbeek, L. Whitehead, S. YeungSUNY Stony Brook, USA

K. De, N. Guler, J. Li, N. OzturkUniversity of Texas at Arlington, USA

A. SandaczInstitute for Nuclear Studies, Warsaw, Poland

* spokesman


Włodek Guryn

p

pp

p

+p

pp

p

Pomeron(C=+1)

Odderon(C=1)+

Perturbative QCD Picture

s = (p1 + p2 )2 = (C.M energy)2 t = (p1 – p3 )2 = - (four momentum transfer)2

s t 1 (GeV/c)2 – Non-perturbative regimeElastic scattering d/dt + optical theorem total cross section tot

OP

OP

AAppppA

AAppppA

−=→

+=→

)(

)(P, O -1Cor 1 C =+=

Vacuum QM exchanged

?

p1

p2

p3

p4

Process of Elastic Scattering


Włodek Guryn

M

Summary of the Existing Data (unpolarized)50 500

PP2PPHighest energy so far:

pp: 63 GeV (ISR)

pp: 1.8 TeV (Tevatron)

pp2pp energy range:

50 GeV s 500 GeV

pp2pp |t|-range:

(at s = 500 GeV)

4•10–4 GeV2 |t | 1.3 GeV2

One cannot assume that because of the existence of the models, the data in pp at the ISR, and pp data at SppS and the Tevatron one can predict with sufficient accuracy d/dt and tot in the RHIC s range.


Włodek Guryn

PP2PP Forward slope B from 2002 engineering run

ddt

= GE

t2

tot2

e+Bt

GE tot

e+½Bt t

+

+

[

]

C

Fit |t |-distribution with

Using fits to world data of tot51.6 mb and 0.13

Fit B for 0.010 GeV2 |t | 0.019 GeV2

B = ( 16.3 1.6 1.0) GeV-2

Depends on detector position

Depends on beam transport element positions

B = ( 16.3 1.6 1. ) GeV-2

Phys. Lett. B 579 (2004) 245-250


Włodek Guryn

Cross sections for polarized beams

€

ANN =σ ↑↑ +↓↓ − σ ↑↓ +↓↑

σ ↑↑ +↓↓ + σ ↑↓ +↓↑ double spin asymmetry

where σ ↑↑ +↓↓ is a cross section with both beams fully polarized along

the normal r n to the scattering plane

ASS has the same definition, but the σ ↑↑ +↓↓ is a cross section for both

beams fully polarized along vector r s in the scattering plane

r s =

r n ×

r p

|r n ×

r p |

, where r p is beam momentum

€

= 0 1+ AN (r P B +

r P Y ) ⋅

r n + ANN (

r P B ⋅

r n )(

r P Y ⋅

r n ) + ASS(

r P B ⋅

r s )(

r P Y ⋅

r s )[ ]

Cross-section, azimutual angular dependence for transversely polarized beams, with polarizations PB and Py:

€

AN =σ ↑ − σ ↓

σ ↑ + σ ↓ is a single spin asymmetry

where σ ↑ is a cross section for one beam fully polarized along normal r n to the scattering plane


Włodek Guryn

Five helicity amplitudes describe proton-proton elastic scattering

Some of the measured quantities are:

flipsingle||),(

flipdouble||),(

flipnon||),(

flipdouble||),(

flipnon||),(

5

4

3

2

1

−←+−⟩⟨++∝−←−+⟩⟨+−∝

−←+−⟩⟨+−∝−←−−⟩⟨++∝

−←++⟩⟨++∝

MtsMtsMtsMtsMts

φφφφφ

€

φi(s, t) = φiem (s, t) + φi

had (s, t)

φ+ = 12(φ1 + φ3)

φ− = 12(φ1 − φ3)

φihad = φi

R + φiAsympt.

€

tot (s) =4π

sIm φ+(s, t)[ ]t =0

, where σ tot gives s dependence of φ+

€

dσ

dt=

2π

s2(| φ1 |2 + | φ2 |2 + | φ3 |2 + | φ4 |2 +4 | φ5 |2) contributes to the shape of AN

Helicity Amplitudes in Elastic Scattering


Włodek Guryn

Source of single spin analyzing power AN

Single spin asymmetry AN arises in the CNI region is due to the interference of hadronic non-flip amplitude with electromagnetic spin-flip amplitude.

Any difference from the above is an indication if other contributions, hadronic spin flip caused by resonance (Reggeon) or vacuum exchange (Pomeron) contributions.

B. Z. Kopeliovich and L. I. Lapidus Sov. J. Nucl. Phys. 114 (19) 1974

N. H. Buttimore, B. Z. Kopeliovich, E. Leader, J. Soffer, T. L. Trueman, Phys. Rev. D59, (1999) 114010.

€

AN (t) =σ ↑ (t) − σ ↓ (t)

σ ↑ (t) + σ ↓ (t)∝

Im[φ5*φ+ ]

dσ / dt

AN (t)

€

φ5 = r5(s)−t

m p

Im1

2(φ1 + φ3) = r5(s)

−t

m p

Imφ+

Published AN Measurements in the CNI Region

pp Analyzing Power

no hadronicspin-flip

-t

AN

(%)

E704@FNALp = 200 GeV/cPRD48(93)3026

E950@BNLp = 21.7 GeV/cPRL89(02)052302

with hadonicspin-flip

no hadronicspin-flip

pC Analyzing Power

r5pC Fs

had / Im F0had

Re r5 = 0.088 0.058

Im r5 = 0.161 0.226

highly anti-correlated


Włodek Guryn

Experimental Determination of AN

Use Square-Root-Formula to calculate spin ( , ) and false asymmetries (, ) .

Since the above is a relative measurement the efficiencies (t, ) cancel €

where δ = P1 P2 ANN cos2 ϕ + ASS sin2 ϕ( ), in our case δ ≤ 0.028

€

AN =σ ↑ − σ ↓

σ ↑ + σ ↓ or AN =

1

Pbeam

N↑ / L↑ − N↓ / L↓

N↑ / L↑ + N↓ / L↓

€

εN (ϕ ) =( P1 + P2) cosϕ ⋅AN

1+ δ=

NL↑↑ (ϕ )NR

↓↓ (π − ϕ ) − NR↑↑ (π − ϕ )NL

↓↓ (ϕ )

NL↑↑ (ϕ )NR

↓↓ (π − ϕ ) + NR↑↑ (π − ϕ )NL

↓↓ (ϕ )Asymmetry

€

εF (ϕ ) =( P1 − P2) cosϕ ⋅AN

1− δ=

NL↑↓ (ϕ )NR

↓↑ (π − ϕ ) − NR↑↓ (π − ϕ )NL

↑↓ (ϕ )

NL↑↓ (ϕ )NR

↓↑ (π − ϕ ) + NR↑↓ (π − ϕ )NL

↑↓ (ϕ )“False”

Asymmetry


Włodek Guryn

Principle of the Measurement

• Elastically scattered protons have very small

scattering angle θ*, hence beam transport

magnets determine trajectory scattered protons

• The optimal position for the detectors is where

scattered protons are well separated from beam

protons

• Need Roman Pot to measure scattered protons

close to the beam without breaking accelerator

vacuum

Beam transport equations relate measured position at the detector to scattering angle.

x0,y0: Position at Interaction Point

Θ*x Θ*y : Scattering Angle at IP

xD, yD : Position at Detector

ΘxD, Θy

D : Angle at Detector

=yD

D

xD

D

y

x

Θ

Θ

*0

*0

y

x

y

x

Θ

Θ

44434241

333231

24232221

141311

aaaa

Laaa

aaaa

aaLa

y

eff

x

eff


Włodek Guryn

The Setup

( ) ( )221121 yxyxpp ΘΘΘΘ −−=⇒−=

→→

,,


Włodek Guryn

The PP2PP Experimental Setup

to IR

Roman Pot

below the beam

Roman Pot above the

beam


Włodek Guryn

Si Detector Package• 4 planes of 400 µm Silicon microstrip detectors:

– 4.5 x 7.5 cm2 sensitive area– good resolution, low occupancy– Redundancy: 2X- and 2Y-detectors– Closest proximity to the beam ~14 mm– 8 mm trigger scintillator with two PMT readout

behind Silicon planes• Run 2003: Silicon manufactured by Hamamatsu

Al strips:512 (Y), 768 (X), 70µm

wide100 µm pitch

implanted resistors

guard ring 1st stripedge: 490 µm

bias ring

SiSi Detector board

Detector board

LV regulationLV regulationSVXIIESVXIIE

Signal/noise 20


Włodek Guryn

Trigger Active area

Acceptance beam pipe shadow

Only “inner” pots used for trigger and analysis, biggest acceptance

Analyze the data for the closest position (¾ of all data)


Włodek Guryn

Elastic Event Identification

An elastic event has two collinear protons, one on

each side of IP

( ) ( )221121 ,, yxyxpp Θ−Θ−=ΘΘ⇒−=

→→

1. It also has eight Si detector “hits”, four on each side.

2. Clean trigger: no hits in the other arm and in inelastic counters.

3. The vertex in (z0) can be reconstructed using ToF.


Włodek Guryn

Hit Correlations Before the CutsEvents with only eight hits

Width is mainly due to

beam emittance

ε = 15 π mm · mrad

spread of vertex position

σz = 60 cm

Note: the background appears enhanced because of the “saturation” of the main band

It is due mainly to beam halo and beam-gas interactions

After the cuts the background in the final sample is ≈ 0.5% ÷ 2% depending on y (vertical) coordinate


Włodek Guryn

Elastic Event Selection

1. Match of coordinates on opposite sides of IP; within 3σ for x and y coordinates.

2. Hit coordinates to be in the acceptance area of the detector.

3. Events with multiple matches were excluded.

After the cuts 1.14 million elastic events in t-interval [0.010, 0.030] (GeV/c)2

Loss of elastic events due to the selections < 0.035


Włodek Guryn

Collinearity:Θx before and after z-correction, and Θy

Θx) = 130 rad Θx) = 100 rad

Θy) = 70 rad


Włodek Guryn

Determination of AN

Use Square-Root-Formula to calculate raw asymmetries.

1. It cancels cancel luminosity dependence and effects of apparatus asymmetries.

2. It uses , bunch combinations.

Since AN is a relative measurement the efficiencies (t, ) cancel

€

εN (ϕ ) =( P1 + P2) cosϕ ⋅AN

1+ δ=

NL↑↑ (ϕ )NR

↓↓ (π − ϕ ) − NR↑↑ (π − ϕ )NL

↓↓ (ϕ )

NL↑↑ (ϕ )NR

↓↓ (π − ϕ ) + NR↑↑ (π − ϕ )NL

↓↓ (ϕ )Asymmetry

€

where δ = P1 P2 ANN cos2 ϕ + ASS sin2 ϕ( ), in our case δ = 0.028


Włodek Guryn

Results: Full bin 0.01 < -t < 0.03 (GeV/c)2

Fit εN cos(φ) dependence to obtain AN

Note: The calculated false asymmetry εF= -0.0011 is consistent with measured εF= -0.0016

PY(+-,-+)=0.476 0.085 PB (+-,-+) =0.430 0.089

PB + PY= 0.8770.149

Arm A Arm B

Statistical errors

εN

PY(++,--)=0.345 0.066 PB (++,--) =0.532 0.106


Włodek Guryn

Systematic Errors on AN

luminosities ans detector efficiencies cancel ----

background 4.5%

beam positions at the detectors 1.8%

corrections to the standard transport matrices 1.4%

uncertainties on Lxeff and Ly

eff 6.4%

neglected term with double-spin asymmetries 2.8%

All above 8.4%

Beam polarization error 17.0%


Włodek Guryn

( )Denom

Nom

m

ttAN

−=

€

Nom = [κ 1 − ρ δ( ) + 2 δ Rer5 − Imr5( ) ]t c

t− 2 Rer5 − ρ Imr5( )

€

Denom =t c

t

⎛ ⎝ ⎜

⎞ ⎠ ⎟2

− 2 ρ + δ( )t c

t+ 1 + ρ 2

( )

where tc = -8πα / σtot and κ is anomalous magnetic moment of the proton

The fit to measured AN(t) gives Re r5 , Im r5

Determination of r5 for pp→pp in the CNI Region


Włodek Guryn

Results: AN and r5

Statistical and systematic errors added in quadratures

17.0% normalisation error due to beam polarisation uncertainty, not included

Re r5 = -0.042 ± 0.037 , Im r5 = -0.51 ± 0.60


Włodek Guryn

stat + sys errors used in fits

prel

imin

ary

with hadronicspin-flip

hadronic spin – flip contribution consistent with zero (1 level)

Im r5 = 0.002 0.029

Re r5 = -0.006 0.007

2/ndf = 10 / 12

( )hadhad

p

had

m

tsr 3155 2)( φφφ +

−=

uncertainty on the( = 0.03) parametercan change at the same level

AN: RHIC Polarized Jet Target s =14 GevA. Bravar, Dubna , Sept. 29, 2005


Włodek Guryn

Reminder: Cross sections for polarized beams

€

ANN =σ ↑↑ +↓↓ − σ ↑↓ +↓↑

σ ↑↑ +↓↓ + σ ↑↓ +↓↑ double spin asymmetry

where σ ↑↑ +↓↓ is a cross section with both beams fully polarized along

the normal r n to the scattering plane

ASS has the same definition, but the σ ↑↑ +↓↓ is a cross section for both

beams fully polarized along vector r s in the scattering plane

r s =

r n ×

r p

|r n ×

r p |

, where r p is beam momentum

€

= 0 1+ AN (r P B +

r P Y ) ⋅

r n + ANN (

r P B ⋅

r n )(

r P Y ⋅

r n ) + ASS(

r P B ⋅

r s )(

r P Y ⋅

r s )[ ]

Cross-section, azimutual angular dependence for transversely polarized beams, with polarizations PB and Py:

€

AN =σ ↑ − σ ↓

σ ↑ + σ ↓ is a single spin asymmetry

where σ ↑ is a cross section for one beam fully polarized along normal r n to the scattering plane


Włodek Guryn

Calculation of double spin asymmetries

€

δ(ϕ ) =N+ + (ϕ ) / L+ + + N−− (ϕ ) / L−− − N+− (ϕ ) / L+− − N− + (ϕ ) / L− +

N+ + (ϕ ) / L+ + + N−− (ϕ ) / L−− + N+− (ϕ ) / L+− + N− + (ϕ ) / L− +

Luminosity normalization is done using:

1.The machine bunch intensities:Lij~I

i

B·Ij

Y

over bunches with given i,j combination

2.The inelastic counters

The two methods agreed.

Distributions δ(φ) were fitted with

(P1·sin2φ+ P2·cos2φ) where

P1=PB·PY·ASS and P2=PB·PY·ANN

Raw asymmetry:

Statistical errors only

PRELIMINARY

€

δ(ϕ ) = PBPY (ASS cos2(ϕ ) + ANN sin2(ϕ ))


Włodek Guryn

Results: ANN and ASS

|t|-range, (GeV/c)2

<|t|>, (GeV/c)2

ASS Ass (stat.) ANN Ann (stat.)2/n

0.010-0.030 0.019 -0.0067 0.0056 0.0248 0.0154 25.3/20

E.Leader, T.L. TruemanPRD 61 077504 (2000)

2/+=0.05(1+i)

iT.L. TruemanOdderon Searches at RHIC WorkshopSept. 2005


Włodek Guryn

Future Program: PP2PP and STARPhysics Processes I

In t-channel it is an exchange with quantum numbers of vacuum

p p

p p

Non Pert. QCD

p p

p p

PQCD picturep p

p p


Włodek Guryn

Physics Processes II

Gluon LaddersGluonic Exchanges

These processes are mediated by gloun rich exchanges


Włodek Guryn

Elastic and Inelastic Processes

In terms of QCD, Pomeron exchange consists of the exchange of a color singlet combination of gluons. Hence, triggering on forward protons at high (RHIC)

energies predominantly selects exchanges mediated by gluonic matter.

For each proton vertex one hast four-momentum transfer p/p MX invariant mass


Włodek Guryn

Central Production in DPE

In the double Pomeron exchange process each proton “emits” a Pomeron and the two Pomerons interact producing a massive system MX.

The massive system could form resonances or consist of jet pairs. Because of the constraints provided by the double Pomeron interaction, glueballs, and other states coupling preferentially to gluons, will be produced with much reduced backgrounds compared to standard hadronic production processes.


Włodek Guryn

Time Projection Chamber: 45 padrow, 2 meters (radius), dE/dx)8%, -1<

Multi-gap Resistive Plate Chamber TOFr: 1 tray (~1/200), (t)=85ps

STAR Detector


Włodek Guryn

STAR Detector

Forward Detector (FPD)

• Pb-glass EM calorimeter

• Shower-Maximum Detector (SMD)

• Preshower

STARSTAR TPC: -1.0 < < 1.0

FTPC: 2.8 < < 3.8

FPD: || 3.8 (p+p)

|| 4.0 (p+p, d+Au)


Włodek Guryn

TPC dE/dx at low pT

M. Anderson et al., Nucl. Instrum. Meth. A 499, 659 (2003)


Włodek Guryn

Resonance Signal in p+p and Au+Au collisions from STAR

K(892)

(1520)

p+p

p+p

Au+Au

Au+Au

(1385)

p+pAu+Au

(1020) p+p

Au+Au

p+p


Włodek Guryn

Leading particle spectra`

Charged hadron pT distributions measured up to 12 GeV in Au+Au, d+Au and p+p reference


Włodek Guryn

Implementation at RHIC

Need detectors to tag forward protons and detector with good acceptance and particle ID to measure central system

Roman Pots of pp2pp and STAR


Włodek Guryn

Physics with Tagged Forward Protons with the STAR Detector at RHIC

H. SpinkaArgonne National Laboratory, USA

R.E. Chrien, R. Gill, W. Guryn*, B. Hackenburg, J. Landgraf, T.A. Ljubičič, D. Lynn,C. Pearson, P. Pile, S. Tepikian, K. YipBrookhaven National Laboratory, USA

A. A. Bogdanov, S.B. Nurushev, M.F RuntzoMoscow Engineering Physics Institute (MEPHI), Moscow, Russia

I. G. Alekseev, V. P. Kanavets, L. I. Koroleva, B. V. Morozov, D. N. SviridaITEP, Moscow, Russia

B. SurrowMIT, Boston USA

S. Khodinov, M. RijssenbeekSUNY Stony Brook, USA

A.Sandacz Soltan Institue for Nuclear Studies, Warsaw, Poland

*Contact personE-mail [email protected] (631) 344 3878

mailto:[email protected]




Włodek Guryn

Acceptance Studies SDD and DPE

Single proton in the Roman Pot Two protons are detected


Włodek Guryn

Summary

1. We have measured the single spin analyzing power AN in polarized pp elastic scattering at s = 200 GeV, highest to date, in t-range [0.01,0.03] (GeV/c)2.

2. The AN is 4-5 from zero.

3. The AN is away from a CNI curve, which does not have hadronic spin flip amplitude.

4. In order to understand better underlying dynamics one needs to map s and t-dependence of AN and also measure other spin related variables (ANN, ASS, ALL, ASL).

5. Preliminary result on ANN, ASS has been obtained.

6. The program of elastic scattering measurements will continue by joining STAR experiment.


Włodek Guryn

Summary

The physics program of tagged forward protons with STAR at RHIC can:1. Study standard hadron diffraction both elastic and inelastic and its spin

dependence in unexplored t and s range;2. Study the structure of color singlet exchange in the non-perturbative

regime of QCD.3. Search for central production of light and massive systems in double

Pomeron exchange process - glueballs.4. Search for an Odderon - an eigenstate of CGC.5. At RHIC II one would take advantage of smaller TPC, include more

coverage to better characterize rapidity gaps.

Those studies will add to our understanding of QCD in the non-perturbative regime where calculations are not easy and one has to be

guided by measurements.

There is a great potential for important discoveries


Włodek Guryn

Future Possibility – Big Improvement

s (GeV) * |t|-range (Gev/c)2 Typical errors

200 20 m 0.003 < |t| < 0.02B = 0.3, tot= 2 – 3 mb

= 0.007 and AN=0.002

x-y

Full acceptance at s 200 GeV

Without IPM and kicker

With IPM and kicker

dN/dt, 20 meter *,Kicker&IPMIN,mmpotposition(V&H)

3

3

. . . .3 .

-t(GeV/c)

/dN dt

dN/dt

the left – right scattering asymmetry AN arises from the interference of

the spin non-flip amplitude with the spin flip amplitude (Schwinger)

in absence of hadronic spin – flip contributions

AN is exactly calculable (Kopeliovich & Lapidus)

hadronic spin- flip modifies the QED ‘predictions’

hadronic spin-flip usually parametrized as

AN & Coulomb Nuclear Interference

emflipnon

hadflip

hadflipnon

emflipN CCA −− φφ+φφ= **

1)p pp

had

€

φ5had = r5

−t

m p

1

2Im(φ1

had + φ3had )

needed phenomenological input: σtot, ρ, δ (diff. of Coulomb-hadronic phases), also for nuclear targets em. and had. formfactors


Włodek Guryn

ε ~12 10-6m after scraping

BRAHMS & PP2PP (p)

STAR (p)

PHENIX (p)

AGS

LINACBOOSTER

Pol. Proton Source500 A, 300 s

GeVs

cmsL

50050

onPolarizati%70

102 2132max

K=

×= −−

Spin Rotators

Partial Siberian Snake

Siberian Snakes

200 MeV Polarimeter AGS Internal Polarimeter

Rf Dipoles

RHIC pC PolarimetersAbsolute Polarimeter (H jet)

2 1011 Pol. Protons / Bunchε = 20 mm mrad

AGS pC Polarimeters

Strong AGS Snake

pp Collider at RHIC


Włodek Guryn

Hit selection in Si detectors


Włodek Guryn

Acceptance Study DPE

Two protons are detected


Włodek Guryn

Reconstruction of the Momentum Loss

€

x1 = a1x0 + L1Θx + η1ξ ; detection point 1

x2 = a2x0 + L2Θx + η 2ξ ; detection point 2

€

Θ x

ξ

⎛

⎝ ⎜

⎞

⎠ ⎟=

1

Det

η 2; − η1

−L2; − L1

⎛

⎝ ⎜

⎞

⎠ ⎟x1 − a1x0

x2 − a2x0

⎛

⎝ ⎜

⎞

⎠ ⎟

Accelerator transport

1. Need to measure vector at the detection point, hence two RPs are needed on each side of STAR.

2. For a proton, which scatters with Θ and we have:


Włodek Guryn

ANN and ASS

The spin dependent elastic cross section is:

=0[1+AN(Pb+Py)n+ANN(Pbn)(Pyn)+ASS(Pbs)(Pys)] wheren-unit vector of normal to scattering plane,k=p/|p| is p-beam momentums=nk Note: s is not radial

In the case of both beams polarized vertically:

=0[1+AN(Pb+Py)cosφ+PbPy(ANNcos2φ+ASSsin2φ)]

Due to vertical orientation of RP (φ=/2) pp2pp in run 2003 was more sensitive to ASS than to ANN.


Włodek Guryn

ANN, ASS raw asymmetries

Distributions δ(φ) were fitted with (P1·sin2φ+ P2·cos2φ)

P1=PB·PY·ASS and P2=PB·PY·ANN

Statistical errors only

PRELIMINARY

Fermilab Nov. 30, 2005 Włodek Guryn Results from the PP2PP Experiment at RHIC and Future Plans...

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Transcript of Fermilab Nov. 30, 2005 Włodek Guryn Results from the PP2PP Experiment at RHIC and Future Plans...