1. IN-MEDIUM FORMATION OF QUARKONIUM (“RECOMBINATION”) R. L. THEWS UNIVERSITY OF ARIZONA SQM2006 UCLA MARCH 26-31, 2006

2. IN-MEDIUM FORMATION HIGH ENERGY EVOLUTION OF MATSUI-SATZ: R plasma screening < R quarkonium SUPPRESSION in a static medium, or KHARZEEV-SATZ: Ionization with deconfined gluons Charm pair diffuse away, will not recombine during deconfinement phase or at hadronization NEW SCENARIO AT COLLIDER ENERGIES

3. Multiple ccbar pairs in high energy AA Collisions 10-15 from extrapolation of low energy 20 from PHENIX electrons 40 from STAR electrons and K  CENTRAL VALUES AT RHIC: AND AT LHC: 100-200??

4. PROBE REGION OF COLOR DECONFINEMENT WITH MULTIPLE PAIRS OF HEAVY QUARKS Avoids Matsui-Satz Condition Form Quarkonium directly in the Medium Formation and Suppression Competition Scenario supported by lattice calculations of quarkonium spectral functions (J/ y and h c )

5. IF THE INCOHERENT RECOMBINATION OF HEAVY QUARKS DETERMINES FINAL HADRONIC ABUNDANCES:

6. QUARKONIUM FORMATION MODELS IN REGION OF COLOR DECONFINEMENT STATISTICAL HADRONIZATION: P. Braun-Munzinger, J. Stachel, Phys. Lett B490 (2000) 196 [nucl-th/0007059]. KINETIC IN-MEDIUM FORMATION: R. L. Thews, M. Schroedter, J. Rafelski, Phys. Rev. C63 (2001) 054905 [hep-ph/0007323].

7. IF THE INCOHERENT RECOMBINATION OF HEAVY QUARKS DETERMINES FINAL HADRONIC ABUNDANCES:IF THE INCOHERENT RECOMBINATION OF HEAVY QUARKS DETERMINES FINAL HADRONIC ABUNDANCES: IN-MEDIUM FORMATION R. L. Thews, M. Schroedter, J. Rafelski, Phys. Rev. C63 (2001) 054905 [hep-ph/0007323]. L. Grandchamp, R. Rapp, Phys. LettB52360 (2001) [hep-ph/0103124]. L. Grandchamp, R. Rapp, G. E. Brown Phys Rev Lett 92, 212301 (2004).

11. Suppression of Initially Produced J/y

12. Continuous In-Medium Formation followed by Partial Suppression

13. COMPARISON WITH INITIAL PHENIX DATA AT RHIC 200 Rates very sensitive to quark momentum distribution Centrality signature varies with magnitude of N cc Initial indication for suppression below binary scaling Agreement within a region of model parameter space

14. Kinetic Model Statistical Model predictions very sensitive to N cc and distribution Therm+Form

15. + Model predictions very sensitive to N cc and distribution

22. R. L. Thews and M. L. Mangano Phys. Rev. C73, 014904 (2006) [nucl-th/0505055] 1.Generate sample of ccbar pairs from NLO pQCD (smear LO q t ) 2.Supplement with k t to simulate initial state and confinement effects 3.Integrate formation rate using these events to define particle distributions (no cquark-medium interaction) 4.Repeat with cquark thermal+flow distribution (maximal cquark-medium interaction) CAN Y AND P T SPECTRA PROVIDE SIGNATURES OF IN-MEDIUM FORMATION?

23. All combinations of c and cbar contribute Total has expected (N ccbar ) 2 / V behavior Prefactor is integrated flux per ccbar pair

25. P T distribution shows minimal variation with y interval

29. p-p data “select” unbiased diagonal c-cbar pairs

30. p-p data determine intrinsic k t

31. Use dAu broadening to determine nuclear k t

32. S. Gavin and M. Gyulassy, Phys. Lett. B214 (1988) Nuclear broadening from Initial state parton scattering, extract l 2 = 0.56 +/- 0.08 GeV 2 for Au-Au at RHIC, compare with 0.12 +/-.02 GeV 2 at fixed-target energy. Note: l and n are correlated within given nuclear geometry.

33. Formation through “off-diagonal” pairs narrows rapidity distribution

36. Formation through “off-diagonal” pairs narrows p t distribution

39. Comparison with Thermal + Transverse Flow c-Quark Distributions K.A.Bugaev, M. Gazdzicki, M.I.Gorenstein, Phys.Lett.B544,127(2002) S.Batsouli, S.Kelly, M.Gyulassy, J.L.Nagle, Phys.Lett.B557,26 (2003)

43. Comparison with coalescence model: V Greco, C. M. Ko, R. Rapp, Phys. Lett. B595:202 (2004)

75. R AA (N coll ) points toward In-Medium Formation (AKA regeneration, coalescence, recombination) as the mechanism for J/y production in central Au-Au at RHIC. However, sequential suppression remains viable option. Must pin down many model parameters (N open charm ), system volume V(t) and temperature T(t), flow, etc. Normalized p T and y spectra alone can provide signatures of in-medium recombination processes The difference of pQCD vs thermal+flow quark pair distributions survives in the J/y spectra Variation of with system size and centrality provides characteristic signals of in-medium formation SUMMARY

76. Initial PHENIX measurements of differ between rapidity intervals, not allowed if J/y reflects underlying ccbar pair distributions. Subject to large uncertainties, the in-medium scenario may be preferred. Initial PHENIX measurements of y spectra do not exhibit narrowing predicted by in-medium formation Thermal + flow charm quarks lead to extremely small, combination with initial production required J/y flow work in progress What about sQGP? Can we retain a scenario of binary interactions? Perhaps charm quarks will not even propagate in the medium.