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Understanding Quarkonia above Deconfinement. Ágnes Mócsy. potential models can reproduce some qualitative features of the heavy quarkonia lattice spectral functions survival of 1S state and melting of 1P state
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Hard Probes June 9-16 06 Understanding Quarkonia above Deconfinement Ágnes Mócsy
Hard Probes June 9-16 06 • potential models can reproduce some qualitative features of the heavy quarkonia lattice spectral functions survival of 1S state and melting of 1P state • but the temperature-dependence of the correlators and quarkonia properties is not reproduced true for all temperature-dependent screened potentials • screening is not responsible for quarkonia suppression tscreening>tQQ conclusion as outline
Hard Probes June 9-16 06 J/(1S) ’(2S) c(1P) 0.9fm 0.7fm 0.4fm T J/ suppression“unambiguous” signal of deconfinement Matsui, Satz 1986 • in QGP color Coulomb force between Q and Q gets screened by q and q • Rscreening < RQQ dissociation of quarkonium at Tc • sequential suppression • modification of quarkonia properties could tell us about deconfinement why heavy QQ is interesting
Hard Probes June 9-16 06 Phenomenology potential models Experiments PHENIX,STAR Theory lattice how we study QQ
Hard Probes June 9-16 06 correlationfunctions of hadronic currents reliably calculated spectral function (,T) M E M c0 Umeda Hatsuda,Asakawa Datta et al 04 Petreczky et al 06 Petreczky et al 06 1P charmonium is gone at 1.16Tc from
Hard Probes June 9-16 06 contradiction with early potential model predictions Datta et al 04 1S charmonium survives up to 1.5Tc correlatorspectral function does not change spectral function properties do not change from
Hard Probes June 9-16 06 • At what temperature do heavy quark bound states disappear? • Can modification of quarkonia properties be understood via a temperature-dependent screened potential? • If yes, what is the potential? • If not, what is the mechanism behind quarkonia melting?
Hard Probes June 9-16 06 assumption: Q-Q interactions are mediated by a potential we don’t know assume a temperature-dependent potential V(r,T) & solve Schrödinger’s equation to obtain properties of QQ V(r) T = 0 confined deconfined J/ T > Tc r potential MODEL
Hard Probes June 9-16 06 Karsch,Mehr,Satz, 88 • screened Cornell potential: • fitted lattice internal energy: • Wong potential: mixture of lattice internal & free energy E.Shuryak,I.Zahed, 044 C.Y.Wong 05 screened potentials
Hard Probes June 9-16 06 bound states/resonances + continuum Mi(T) bound state mass Fi(T) amplitude S0(T) threshold AM, P.Petreczky, EuroPhysJC (05) PRD 73 (06) hep-ph/0606053 = + model spectral function
Hard Probes June 9-16 06 the c0 is gone just above Tc in agreement with lattice c0correlator
Hard Probes June 9-16 06 • c correlator does not agree with lattice increase due to continuum, decrease due to amplitude reduction • change in the spectral function disagrees with lattice feature for all screened potentials ccorrelator
Hard Probes June 9-16 06 S-wave lattice internal energy Wong potential • potential models still fail • drastic change of mass & amplitude of 1S state • inconsistent with lattice • even though 1S survives in some screened potentials the spectral function is strongly modified AM,Petreczky, hep-ph/0606053 AM,Petreczky,Casalderrey-Solana, in prep non-relativistic Green’s function
Hard Probes June 9-16 06 AM, hep-ph/0606124 no temperature-dependent screening • no modification of the 1S properties - use PDG • melting of 2S and 3S states • melting of the 1P state • continuum threshold s0 reduction T = 0 T Tc s0 s0 1S 2S 3S 1P instead consider a toy model
Hard Probes June 9-16 06 c0 c choice of s0 can keep correlators as seen on the lattice: c unchanged & c0 increased compensate for the melting of higher excited states above Tc with the decrease of the threshold the toy model
Hard Probes June 9-16 06 Kharzeev,AM, in prep Rate of escape into the continuum binding energy • T >> EQQ screening • weak coupling • continuum dominates • all states modified • T << EQQ gluo-effect • strong coupling • discrete states dominate • ground state unaffected T>Tc gluon sector dominates talk by F.Karsch Kharzeev,McLerran, Satz 95 Shuryak 78 Bhanot, Peskin 79 what is the dissociation mechanism
Hard Probes June 9-16 06 • temperature-dependent screened potentials inconsistent with lattice QCD • screening not responsible for quarkonia dissociation • we are in the strong coupling regime where dissociation is due to gluons stay tuned, you’ll here more soon … conclusion
Hard Probes June 9-16 06 Péter Petreczky Dima Kharzeev Jorge Casalderrey-Solana thanks a lot
Hard Probes June 9-16 06 ccorrelator
Hard Probes June 9-16 06 AM, P.Petreczky, hep-ph/0606053 AM, P.Petreczky, J.Casalderrey-Solana, in prep another way to obtain the spectral function include many body effects non-relativistic Green’s function