N*ews from COSY May 2011 | Hans Ströher (Forschungszentrum Jülich, Germany)

Selected recent results N*ews from COSY – Outline COSY-facility Detection systems Selected recent results 2 2

COSY N*ews from COSY – Storage Ring Cooler and storage ring for (polarized) protons and deuterons p = 0.3 – 3.7 GeV/c Phase space cooled internal & extracted beams COSY e-Cooler Injector cyclotron 3

… the machine for spin physics N*ews from COSY – Storage Ring Cooler and storage ring for (polarized) protons and deuterons p = 0.3 – 3.7 GeV/c Phase space cooled internal & extracted beams COSY e-Cooler … the machine for spin physics with hadron beams Injector cyclotron 4

N*ews from COSY – Experiments Hadron physics with hadronic probes Experimental set-ups: ANKE WASA EDM TOF NEW: PAX WASA ANKE EDM PAX TOF

N*ews from COSY – Experiments Hadron physics with hadronic probes Experimental set-ups: ANKE WASA EDM TOF NEW: PAX WASA ANKE EDM PAX TOF Future plan/project: srEDM

N*ews from COSY – Experiments 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: ~4p electromagnetic calorimeter thin superconducting solenoid hydrogen, deuterium pellet target symmetries and symmetry violation

N*ews from COSY – Experiments 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: ~4p electromagnetic calorimeter thin superconducting solenoid hydrogen, deuterium pellet target symmetries and symmetry violation

N*ews from COSY – Experiments 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: ~4p electromagnetic calorimeter thin superconducting solenoid hydrogen, deuterium pellet target symmetries and symmetry violation

COSY N*ews from COSY – General N N  N N*  [N N] X (= g, p, h, …) NN fusion: p N(+)  (N N*)+(+)  d p(+) D-resonance Mostly: no resonance structure, since 3(4)-body phase-space & strong FSI  invariant mass distributions COSY HADES at GSI 10 10

COSY N*ews from COSY – General N N  N N*  [N N] X (= g, p, h, …) Special cases, e.g. p p  p p p0p0 Roper COSY WASA at CELSIUS 11 11

COSY N*ews from COSY – General N N  N N*  N K Y (hyperons) Isospin (-filter): K L only N* resonances, e.g. N*(1650, 1675, 1680,1700, 1710, 1720, 1840, 1875, 1900) K S both N* and D* resonances, e.g. D*(1600, 1620, 1700, 1750, 1900) Polarization (target, beam): K+, p, L asymmetries, L polarization COSY 12 12

N*ews from COSY – Results (I) p p  p K+ Y0 (Y0 = L, S0) TOF 13 13

N*ews from COSY – pp  pK+ (L;S0) Reaction: pp  p K+ (p p-) 3 beam energies: pp = 2.95 GeV/c (QL = 204, QS = 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 14

N*ews from COSY – pp  pK+ (L;S0) Reaction: pp  p K+ (p p-) 3 beam energies: pp = 2.95 GeV/c (QL = 204, QS = 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) 15

N*ews from COSY – pp  pK+ (L;S0) Reaction: pp  p K+ (p p-) 3 beam energies: pp = 2.95 GeV/c (QL = 204, QS = 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: (2) L case (239 MeV): complete coverage cms frame: cos(q)= 0 symmetric Jackson-frames helicity-frames 16

N*ews from COSY – pp  pK+ (L;S0) Reaction: pp  p K+ (p p-) 3 beam energies: pp = 2.95 GeV/c (QL = 204, QS = 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: (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 pL K+p 17

N*ews from COSY – pp  pK+ (L;S0) Reaction: pp  p K+ (p p-) 3 beam energies: pp = 2.95 GeV/c (QL = 204 MeV); 3.20 GeV/c (284 MeV) 3.30 GeV/c (316 MeV) Primary and secondary V-shape; charged multiplicity jump; ToF 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) 18

N*ews from COSY – pp  pK+ (L;S0) Reaction: pp  p K+ (p p-) 3 beam energies: pp = 2.95 GeV/c (QL = 204, QS = 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: (4) S0 case (162 MeV): complete coverage small statistics cms frame Jackson-frames helicity-frames differences to L 19

N*ews from COSY – pp  pK+ (L;S0) Next: additional high-statistics data  PWA (i) upgraded detector (STT) (ii) polarized proton beam (2.95 GeV/c) pb = 2.95 GeV/c P = (61 +- 2) % 20

N*ews from COSY – pp  pK+ (L;S0) 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/c P = (61 +- 2) % 21

N*ews from COSY – Results (II) p p  n K+ S+ ANKE, COSY-11 HIRES 22 22

N*ews from COSY – pp  n K+ S+ Reaction: pp  K+ n X (COSY-11) pp  K+ X ; (K+p) X ; (K+p+) 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-section clearly excluded  no D* ++ (1620) contribution needed s [µb] 23

N*ews from COSY – Results (III) p p  p p w (Resonances?) TOF 24 24

N*ews from COSY – pp  pp w Reaction: pp  p p p+p- X 3 beam energies: pp = 2.95 GeV/c (Qw = 92 MeV); 3.06 GeV/c (128 MeV) 3.20 GeV/c (173 MeV) 4 charged particles; ToF; missing p0 Result: (1) COSY-TOF collaboration, EPJ A 44, 7 (2010) w via missing mass „… no obvious indication of w- production via N* resonances found …“ 25

N*ews from COSY – Results (IV) p p  {pp}s g (D(1232)) ANKE 26 26

N*ews from COSY – pp  {pp}s g Reaction: pp  pp X (X = g, p0) 6 beam energies: Tp = 353 … 800 MeV 2 protons, DEpp < 3MeV  1S0 (Diproton); qlab < 20° Result: (1) ANKE collaboration, J.Phys. G 37, 105005 (2010) missing mass analysis p0 dominating; clear g-contribution 27

N*ews from COSY – pp  {pp}s g Reaction: pp  pp X (X = g, p0) 6 beam energies: Tp = 353 … 800 MeV 2 protons, DEpp < 3MeV  1S0 (Diproton); qlab < 20° Result: (2) energy dependence shows resonant behavior; comparison with pn  d g D-resonance shifted, smaller width (note: no M1 possible) WASA/Promise result (Uppsala) – covers much larger angular range 28

p n  d p0p0 (ABC-Effect) WASA 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“ 29 29

N*ews from COSY – pp  pp p0p0 high energies near threshold pp→pN*(1440) pp→∆ ∆(1232) p π p π π ∆ (1232) π p π 30

N*ews from COSY – pn  d p0p0 Reaction: pd  d p0p0 pspectator ; d and p0p0 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) 31

N*ews from COSY – pn  d p0p0 Reaction: pd  d p0p0 pspectator ; d and p0p0 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: (2) Maximum (2.38 GeV) Off-peak (2.50 GeV) 32

N*ews from COSY – pn  d p0p0 Reaction: pd  d p0p0 pspectator ; d and p0p0 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: (2) 33

N*ews from COSY – pn  d p0p0 Reaction: pd  d p0p0 pspectator ; d and p0p0 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: (3) What is this? independently normalized Mass ~ M(DD) - 80 MeV Width ~ ¼ of G(DD) 34

N*ews from COSY – pn  d p0p0 Reaction: pd  d p0p0 pspectator ; d and p0p0 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: (3) Roper-contribution (R  Dp  Npp) 35

N*ews from COSY – pn  d p0p0 Reaction: pd  d p0p0 pspectator ; d and p0p0 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: (3) t-channel DD-contribution (from pp  d p+p0 via isospin) 36

N*ews from COSY – pn  d p0p0 Reaction: pd  d p0p0 pspectator ; d and p0p0 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: (3) s-channel resonance at M = 2.37 GeV and G = 68 MeV 37

N*ews from COSY – pn  d p0p0 Reaction: pd  d p0p0 pspectator ; d and p0p0 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: (4) Next: (i) pn  pn p0p0, (ii) pol. d-beam (i.e. np  d p0p0), (iii) pn elastic pn  R(3+)  DD  dp0p0 J=3 J=1 38

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?) 39

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?) 40

N*ews from COSY – Information pp  pp m 41 41