N*ews from COSY

Mit

glie

d d

er

Helm

holt

z-G

em

ein

sch

aft

N*ews from COSY

May 2011 | Hans Ströher (Forschungszentrum Jülich, Germany)

22. April 2023 Institut für Kernphysik (IKP) Folie 2

COSY-facility

Detection systems

Selected recent results

N*ews from COSY – Outline


Cooler and storage ring for (polarized) protons and deuterons

p = 0.3 – 3.7 GeV/c

Phase space cooled internal & extracted beams

Injector cyclotron

N*ews from COSY – Storage Ring

e-CoolerCOSY


Cooler and storage ring for (polarized) protons and deuterons

p = 0.3 – 3.7 GeV/c

Phase space cooled internal & extracted beams

Injector cyclotron

N*ews from COSY – Storage Ring

COSY

… the machine for spin physics with hadron beams

e-Cooler


N*ews from COSY – Experiments

Hadron physics with hadronic probes

Experimental set-ups:

ANKE WASA EDM

TOF

NEW:

PAX

PAX

EDM

WASA

ANKE

TOF



Hadron physics with hadronic probes

Experimental set-ups:

ANKE WASA EDM

TOF

NEW:

PAX

Future plan/project:srEDM

PAX

EDM

WASA

ANKE

TOF



ANKE: forward magnetic spectrometer solid, gas-jet, polarized targets

double polarization experiments

TOF: large acceptance non-magnetic det. liquid hydrogen, deuterium targets

(non-)strange meson, hyperon prod.

WASA: ~4 electromagnetic calorimeter thin superconducting solenoid hydrogen, deuterium pellet target

symmetries and symmetry violation


COSY

N N N N* [N N] X (= …)

NN fusion: p N(+) (N N*)+(+) d (+)

-resonance

Mostly: no resonance structure, since3(4)-body phase-space & strong FSI

invariant mass distributions

N*ews from COSY – General

HADES at GSI


N N N N* [N N] X (= …)

Special cases, e.g. p p p p 00

WASA at CELSIUS

Roper


COSY


COSY

N N N N* N K Y (hyperons)

Isospin (-filter):

Konly N* resonances, e.g.N*(1650, 1675, 1680,1700,1710, 1720, 1840, 1875, 1900)

K both N* and * resonances, e.g.D*(1600, 1620, 1700, 1750, 1900)

Polarization (target, beam):

K+, p, asymmetries, polarization



p p p p p K p K++ Y Y00

(Y(Y00 = = 00))

TOFTOF

N*ews from COSY – Results (I)


N*ews from COSY – pp pK+ (0)

Reaction: pp p K+ (p -)

3 beam energies: pp = 2.95 GeV/c (Q = 204, Q = 124 MeV); 3.06 GeV/c (239, 162 MeV); 3.20 GeV/c (284, 207 MeV)

Primary and secondary V-shape; charged multiplicity jump; ToF






Result: (1) COSY-TOF collaboration, EPJ A 46, 27 – 44 (2010)






Result: (2) case (239 MeV):

complete coverage

cms frame:cos(= 0 symmetric

Jackson-frames

helicity-frames






Result: (3) helicity-frames:

strong evidence for:

N*(1650)S11

N*(1710)P11 and/or N*(1720)P13

unlikely:

N*(1675)D15

N*(1680)F15

N*(1700)D13

p K+p




3 beam energies: pp = 2.95 GeV/c (Q = 204 MeV); 3.20 GeV/c (284 MeV) 3.30 GeV/c (316 MeV)


Result: (3) COSY-TOF collaboration, PL B 688, 142 (2010)

Dalitz-plot analysis

Importance of N*(1650)compared to N*(1710) N*(1720)

2.85 GeV/c … TOF (2006)






Result: (4) 0case (162 MeV):

complete coveragesmall statistics

cms frameJackson-frameshelicity-frames

differences to



Next: additional high-statistics data PWA

(i) upgraded detector (STT) (ii) polarized proton beam (2.95 GeV/c)

pb = 2.95 GeV/cP = (61 +- 2) %



Next: additional high-statistics data PWA

(i) upgraded detector (STT) (ii) polarized proton beam (2.95 GeV/c)

PAC39 (May 2011) allocated 9 weeks to finalize physics program;after that TOF will be decomissioned in 2012.

pb = 2.95 GeV/cP = (61 +- 2) %


p p p p n K n K++ ++

ANKE, ANKE, COSY-11COSY-11

HIRESHIRES

N*ews from COSY – Results (II)


N*ews from COSY – pp n K+ +

Reaction: pp K+ n X (COSY-11)pp K+ X ; (K+p) X ; (K++) X (ANKE)pp K+ X (HIRES)

Result: (1) COSY-11 collaboration, PL B 643, 251 (2006)ANKE collaboration, PR C81, 045208 (2010)HIRES collaboration, PL B 692, 10 (2011)

Disappointing expt´l situation, but:

very high X-sectionclearly excluded

no * ++ (1620) contribution needed

[µb]


p p p p p p p p

(Resonances?)(Resonances?)

TOFTOF

N*ews from COSY – Results (III)


N*ews from COSY – pp pp

Reaction: pp p p - X

3 beam energies: pp = 2.95 GeV/c (Q = 92 MeV); 3.06 GeV/c (128 MeV) 3.20 GeV/c (173 MeV)

4 charged particles; ToF; missing 0

Result: (1) COSY-TOF collaboration, EPJ A 44, 7 (2010)

via missing mass

„… no obvious indication of -production viaN* resonances found …“


p p p p {pp} {pp}ss

(((1232))(1232))

ANKEANKE

N*ews from COSY – Results (IV)


N*ews from COSY – pp {pp}s

Reaction: pp pp X (X = , 0)

6 beam energies: Tp = 353 … 800 MeV

2 protons, Epp < 3MeV 1S0 (Diproton); lab < 20°

Result: (1) ANKE collaboration, J.Phys. G 37, 105005 (2010)

missing mass analysis

0 dominating;clear -contribution


N*ews from COSY – pp {pp}s

Reaction: pp pp X (X = , 0)

6 beam energies: Tp = 353 … 800 MeV

2 protons, Epp < 3MeV 1S0 (Diproton);lab < 20°

Result: (2) energy dependence shows resonantbehavior;

comparison withpn d

-resonanceshifted, smaller width

(note: no M1 possible)

WASA/Promise result (Uppsala) – covers much larger angular range


p n p n d d 0000

(ABC-Effect)(ABC-Effect)

WASAWASA

N*ews from COSY – Results (V)

May 18,2011 - Session II-C (15:20)T. Tolba; „Double pion production in pp-interactions at Tp = 1.4 GeV“


N*ews from COSY – pp pp 00

pp ppππ

high energiesnear threshold

pp→pN*(1440)

p π π ∆ (1232) π

p π

pp→∆ ∆(1232)

p π p π


N*ews from COSY – pn d 00

Reaction: pd d 00 pspectator ; d and 00 detected

3 beam energies: Tp = 1.0, 1.2, 1.4 GeV; Fermi momentum

Effective energy ranges: 2.22 – 2.36; 2.33 – 2.44; 2.42 – 2.56 GeV

Result: (1) WASA-Collaboration, submitted PRL (2011)






Result: (2)

Maximum (2.38 GeV) Off-peak (2.50 GeV)






Result: (2)






Result: (3)

What is this?

independently normalized

Mass ~ M() - 80 MeV

Width ~ ¼ of ()






Result: (3)

Roper-contribution (R N)






Result: (3)

t-channel -contribution (from pp d +0 via isospin)






Result: (3)

s-channel resonance at M = 2.37 GeV and = 68 MeV






Result: (4)

Next: (i) pn pn 00, (ii) pol. d-beam (i.e. np d00), (iii) pn elastic

J=1

J=3

pn R(3+) d00


N*ews from COSY – Summary

Part of the ongoing COSY program devoted to N* physics(NN- and NY-interaction (ANKE, TOF), symmetries (WASA), …)

Hyperon production at TOF extension to pol. beams PWA

ABC-resonance at WASA nature (s-channel resonance?)


N*ews from COSY – Information

pp pp m

N*ews from COSY

Documents

Transcript of N*ews from COSY