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ECT* Trento, July 3-7, 2006 Study of Hadron in-Medium Properties in Antiproton-Nucleus Collisions A. Gillitzer Institut fr Kernphysik Forschungszentrum Jlich

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A. Gillitzer, ECT* Trento, July 3-7, 2006 Outline _ Interaction of charmed hadrons with matter J/ and absorption In-medium mass of D mesons In-medium mass of charmonium states pd collisions: DN / DN interaction Hadrons with light anti-quarks in matter Antikaons ( K -, K 0 ) Antibaryons ( p, ) Summary _ _ __ _

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A. Gillitzer, ECT* Trento, July 3-7, 2006 J/ nucleon interaction J/ as indicator for QGP formation in relativistic nucleus-nucleus collisions / Final NA50 result: G. Borges, JPG 30 (2004) S1351; hep-ex/0505065 B. Allessandro et al., EPJC 33 (2004) 31; EPJC 35 (2005) 335 abs = 4.2 0.5 mb J/ abs = 9.6 1.6 mb 400 GeV/c p + A J/ ( ) + X A + A J/ ( ) + X

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A. Gillitzer, ECT* Trento, July 3-7, 2006 J/ nucleon interaction What is known about J/ absorption in nuclei? A. Sibirtsev, K. Tsushima, and A.W. Thomas, Phys. Rev. C 63 (2001) 044906 Data: (1) ~20 GeV + Be, Ta (SLAC) R.L. Andersen et al., Phys. Rev. Lett. 38 (1977) 263 (2) 200, 450, 800 GeV p+A NA38, NA51, E772 analysis: D. Kharzeev et al., Z. Phys. C 74 (1997) 307 (3) NA50 p + A recent (2) (3) (1)

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A. Gillitzer, ECT* Trento, July 3-7, 2006 J/ nucleon interaction Measurement at PANDA : K. Seth, Proc. Hirschegg 2001, p.183 p + A J/ + X + - + X _ note: peak position sensitive to J/ mass shift in medium p + A J/ + X e + e - + X _ measure cross section as function of A and p p deduce J/ N dissociation cross section at lower, well- defned J/ momentum _

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A. Gillitzer, ECT* Trento, July 3-7, 2006 J/ nucleon interaction: feasibility J/ Simulation: p + Cu + - + X background scaled up J/ signature: high p , coplanarity J/ reconstructed with M ~ 20 MeV rate estimate for p p on resonance: at L = 10 31 cm -2 s -1 R J/ (produced) 220 /d scan of p p & variation of A target time consuming _ _ _

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A. Gillitzer, ECT* Trento, July 3-7, 2006 nucleon interaction J/ b pp (2.12 0.10) 10 -3 (2.07 0.31) 10 -4 b (5.88 0.10) 10 -2 (7.3 0.8) 10 -3 tot (91.0 3.2) keV (281 17) keV p p 4.07 GeV/c 6.23 GeV/c branching rates reduced by factor ~80 as compared to J/ enhanced by factor ~3 by larger width yield reduced by factor ~27, i.e. R (produced) 8 /d difficult

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A. Gillitzer, ECT* Trento, July 3-7, 2006 Pseudoscalar mesons in nuclear matter : deeply bound pionic states K + : momentum shift in p+A K - : controversely discussed D : unknown Hayashigaki, PLB 487 (2000) 96 Morath, Lee, Weise, priv. Comm. D-D- 50 MeV D D+D+ vacuum nuclear medium p K 25 MeV 100 MeV K+K+ K-K- p-p- p+p+ Pb A. Sibirtsev et al., Eur. Phys. J. A 6 (1999) 351

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A. Gillitzer, ECT* Trento, July 3-7, 2006 D meson spectral distribution M.F.M. Lutz, C.L. Korpa, PLB 633 (2006) 43 prediction: two-mode structure of D + U D + +32 MeV for main branch resonance-hole state at M ~ 1.6 GeV repulsive D - potential: U D - +18 MeV

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A. Gillitzer, ECT* Trento, July 3-7, 2006 D + meson spectral distribution L. Tolos, J. Schaffner-Bielich, A. Mishra, PRC 70 (2004) 025203 prediction: relatively small D in-medium changes broad double-hump structure of D meson spectral distribution self-consistent D + dressed and N self-consistent D

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A. Gillitzer, ECT* Trento, July 3-7, 2006 D/D-meson mass shift: observables _ caveat: high D momentum Subthreshold DD production enhancement of cross section due to attractive mass shift ( analogy to K production ) A. Sibirtsev, K. Tshusima, A.W. Thomas, Eur. Phys. J. A 6 (1999) 351 quantitative result under discussion D + yield reduced by absorption no information on D mass splitting final states: D - D + X or D - c X rates at T p = 4.5 GeV: ~110 nb, L = 10 31 cm -2 s -1 R ~ f eff x (8608600) /d _ _ + _

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A. Gillitzer, ECT* Trento, July 3-7, 2006 D/D-meson mass shift _ 3 GeV/c 2 Mass 3.2 3.4 3.6 3.8 4 y (1 3 D 1 ) y (1 3 S 1 ) y (2 3 S 1 ) h c (1 1 S 0 ) y (3 3 S 1 ) c c2 (1 3 P 2 ) c c1 (1 3 P 1 ) c c1 (1 3 P 0 ) 3,74 3,64 3,54 vacuum 1r01r0 2r02r0 Ye.S. Golubeva et al., EPJ A 17 (2003) 275 Width of charmonium states close to DD threshold assumes zero mass shift of charmonium states collisional width may dominate measure cc + - / e + e - _ _ (3770)

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A. Gillitzer, ECT* Trento, July 3-7, 2006 D/D-meson mass shifts _ D/D transverse momentum distribution ( J. Pochodzalla, March 05 ) mean transverse momentum shifted by attractive / repulsive potential (see determination of K + potential at ANKE) _ size of effect: for p (D) ~ 3 GeV/c, p (D) ~ 0.3 GeV/c, U = 100 MeV [10 MeV] 4% [0.4%] momentum shift p (D) shift ~12 [1.2] MeV/c; some 10 MeV potential should be visible U K + = +20 3 MeV

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A. Gillitzer, ECT* Trento, July 3-7, 2006 How to get slow D mesons ? threshold D + D - production:p p = 6.44 GeV/c p D 3.2 GeV/c high energy D + D - production:p p = 15 GeV/c p D 1.67 GeV/c nucleon internal momentum:for p = 3 p F, p p = 6.5 GeV/c p D 0.52 GeV/c cooperative pNN process:e.g. pd D - c +, p p = 6.5 GeV/c p D 0.38 GeV/c 2-step process:e.g. D + d head-on collision: M D M d p D 0 slow D large suppression factors conclusion: study of D mesons at rest in nuclei extremely difficult _ _ _ _ _

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A. Gillitzer, ECT* Trento, July 3-7, 2006 Charmonium mass shift Quantum numbers QCD 2 nd Stark eff. Potential model QCD sum rules Effects of DD loop cc 0 -+ 8 MeV [1] 5 MeV [4] J/1 -- 8 MeV [1] -10 MeV [3] 7 MeV [4] < 2 MeV [5] c0,1,2 0,1,2 ++ -40 MeV [2]-60 MeV [2] (3686)1 -- -100 MeV [2]< 30 MeV [2] (3770)1 -- -140 MeV [2]< 30 MeV [2] [1] Peskin, NPB 156 (1979) 365, Luke et al., PLB 288 (1992) 355 [2] S.H. Lee, nucl-th/0310080, Hadron 2003 proceedings [3] Brodsky et al., PRL 64 (1990) 1011 [4] Klingel, Kim, Lee, Morath, Weise, PRL 82 (1999) 3396 [5] Lee, Ko, PRC 67 (2003) 038202

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A. Gillitzer, ECT* Trento, July 3-7, 2006 Charmonium mass shift: observables c J/ c 0,1,2 (3686) (3770) Expected Mass shift -5 MeV to -8 MeV -7 MeV to -10 MeV -40 MeV to -60 MeV -100 MeV to -130 MeV -120 MeV to -140 MeV Observation through e+e-/+-e+e-/+- J/ e+e-/+-e+e-/+- e+e-/+-e+e-/+- p _ ~ 1 fm final state = e + e - / + - / / J/ t ~ 1020 fm/c 10 fm/c (collisional broadening) S.H. Lee (Proc. Hadron 03) predicts few 10100 events/day at L = 2 10 32 cm -2 s -1 ~ f eff (110) events/day at L = 10 31 cm -2 s -1

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A. Gillitzer, ECT* Trento, July 3-7, 2006 Study of D+N reactions _ Study of pd collisions quasi-free D + D - (D 0 D 0,D s D s ) production D/D, D s /D s beam hitting the spectator nucleon __ __ reactions e.g.: D + n D 0 pcharge exchange D + n 0 c charm exchange D + n D s strangeness creation D + n K 0,+ c charm exchange & strangeness creaction D s n D - strangeness exchange etc., + inelastic channels D meson & charmed hyperon resonance spectroscopy ( high s ! ) needs theoretical investigation ( see A. Sibirtsev, NPA 680 (2001) 274c ) + + +,0 - 0

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A. Gillitzer, ECT* Trento, July 3-7, 2006 Antikaons in nuclear matter D.B. Kaplan, A.E. Nelson, PLB 175 (1986) 57, PLB 192 (1987) 193 K/K mass splitting at 0 predicted repulsive for K, (more strongly) attractive for K free KN I = 0 interaction repulsive ( (1405) ) semi-empirical fit of kaonic atoms: C.J. Batty et al., Phys. Rep. 287 (97) 385 U K = - 50 -200 MeV (1405) KN I=0 potential model: U K = -200 MeV, small width Y. Akaishi, T. Yamazaki, PRC 65 (2002) 044005 U K = - 600 MeV with nuclear shrinkage Y. Akaishi et al., PLB 613 (2005) 140 chiral unitarity models U K = -50 -70 MeV, large width M. Lutz, PLB 426 (1998) 12 A.Ramos, E.Oset, NPA 671 (2000) 481 L. Tolos, A. Ramos, E. Oset, nucl-th/0603033 _ _ _

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A. Gillitzer, ECT* Trento, July 3-7, 2006 Observation of bound K - 3N & K - 2N systems ? KEK: 4 He(K - stpd,p/n) T. Suzuki et al., PLB 597 (2004) 263 NPA (2005) 375c B K 190 MeV B K 170 MeV B ppK - 115 MeV FINUDA at DA NE K - stpd on light nuclei M. Agnello et al., PRL 94 (2005) 212303 Interpretation of both KEK and FINUDA data as deeply bound kaonic states critically discussed: E. Oset and H. Toki, nucl-th/0509048 V.K. Magas, E. Oset, A. Ramos, H. Toki, nucl-th/0601013 2-nucleon absorption K - NN N, N More hints: T. Kishimoto et al., NPA 754 (2005) 383c N. Herrmann, Proc. EXA 05, Vienna

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A. Gillitzer, ECT* Trento, July 3-7, 2006 Antikaons in nuclei at PANDA + gate on in final state after nuclear K - absortption JETSET: PLB 345 (1995) 325 reaction: pp ~ recoilless pp 4 b at p = 1.4 GeV/c _ _ kinematics: p p ~ 2 GeV/c : high momentum K + K - : PANDA-FS: max 510 o low momentum K - captured in bound state low momentum K + reconstruct K - potential from K + missing mass _

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A. Gillitzer, ECT* Trento, July 3-7, 2006 p = 4 GeV/c p = 2 GeV/c pp : K +, K - p trans vs. p long distributions _

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A. Gillitzer, ECT* Trento, July 3-7, 2006 Antikaons in nuclei at PANDA Feasibility: rate: R = f eff A target f surv 0.7 10 3 /h at L = 10 31 cm -2 s -1 missing mass resolution: M ~ 18 MeV for p/p = 1% most demanding: detection of low momentum K + K + from decay at rest ( p = 127 MeV/c ): range = 0.5 g/cm 2 (C) requires: - good p/p resolution forward spectrometer - K identification in forward spectrometer - K + identification in MVD by dE/dx - detection of K - N / detailed simulation necessary (K identification, nuclear background) (part)

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A. Gillitzer, ECT* Trento, July 3-7, 2006 K + identification in MVD dE/dx simulation: T. Stockmanns dE/dx of , K , p at p = 0.4 GeV/c separation power vs. momentum p = 400 MeV/c KK p

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A. Gillitzer, ECT* Trento, July 3-7, 2006 Antibaryons in nuclei : p _ _ M (A 1)p from MM p M (A-1) from MM pp _ Study of pA scattering, p-atoms (LEAR): only imaginary potential visible; real part unknown ( 0 - 300 MeV ) NN NN (G-parity) : large attraction recent theoretical study of nuclear p potential: I.N. Mishustin et al. (Frankfurt group), Phys. Rev. C 71 (2005) 035201 predict deep potential & surprisingly small width PANDA: p + A p forward + (A 1) p measure ReU also for large ImU determine (A-1) spectral function with p + A p + p + (A 1) * _ _ _ _ _ __ * _

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A. Gillitzer, ECT* Trento, July 3-7, 2006 Antibaryons in nuclei : p _ Feasibility: d /d (180 o ) = 0.26 mb/sr at p p = 0.7 GeV/c R. Bertini et al., Phys. Lett. B 228 (1989) 531 cm = 20 o lab = 8 o = 100 b (use 50 b for p p ~ 2 GeV/c) rate: R = f eff A target f p 500 /s at L = 10 31 cm -2 s -1 missing mass resolution: M ~ 18 MeV for p/p = 1% momentum resolution of forward spectrometer (p) _ _ (part) _

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A. Gillitzer, ECT* Trento, July 3-7, 2006 Antibaryons in nuclei : _ Nuclear potential Indication for reduced absorption as compared to p absorption from /p ratio, A-dependence in relativistic HI collisions PANDA : ~2 GeV/c p + A forward + (A 1) * detect p - in forward detector: p p - = 101 MeV/c < 3 o d /d pp (180 o ) = 2 b/sr at p = 1.77 GeV/c ~ 1 b P.D. Barnes et al. (LEAR-PS185), Phys. Rev. C 54 (1996) 2831 rate: R = f eff A target f 10 /s _ _ _ _ _ _ _ _ (part) _ _

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A. Gillitzer, ECT* Trento, July 3-7, 2006 Summary Charm in nuclear matter - J/ absorption:first experiments in pA charm + X - D/D production:inclusive D, D, and c detection with nuclear targets sensitivity to D/D potential? - M D/D from cc width:difficult conceptually and experimentally - cc mass shift:cc decay inside nucleus size of cross section ? - pd charm + X:access to DN / DN interaction, c *, c *, c * looks feasible but needs theoretical investigation Antikaons and Antibaryons: K, p, in nuclear matter - implant hadrons inside nuclei at rest - much larger cross sections - requires good p/p resolution of forward spectrometer ( K: slow K + PID ) - promising approach to determine K, p, potential _ _ + _ _ _ _ _ _ _ _ _ _ _ _ _ _ _