Onset of J/ Onset of J/ Melting in Melting in Quark-Gluon Quark-Gluon Fluid at RHIC Fluid at RHIC Taku Gunji Taku Gunji Center for Nuclear Study Center for Nuclear Study University of Tokyo University of Tokyo r: Phys. Rev. C 76:051901 (R), 2007 aboration with: amagaki (CNS, Univ. of Tokyo), atsuda, T. Hirano, Y. Akamatsu (Phys. Dept. Univ. of Tokyo) 1 Quark Matter 2008, Jaipur, India, 2008/2/9
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Onset of J/ Melting in Quark- Gluon Fluid at RHIC Taku Gunji Center for Nuclear Study University of Tokyo Paper: Phys. Rev. C 76:051901 (R), 2007 Collaboration.
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Onset of J/Onset of J/ Melting in Quark-Melting in Quark-
Gluon Fluid at Gluon Fluid at RHICRHICTaku GunjiTaku Gunji
Center for Nuclear StudyCenter for Nuclear StudyUniversity of TokyoUniversity of Tokyo
Paper: Phys. Rev. C 76:051901 (R), 2007 Collaboration with:H. Hamagaki (CNS, Univ. of Tokyo), T. Hatsuda, T. Hirano, Y. Akamatsu (Phys. Dept. Univ. of Tokyo)
1Quark Matter 2008, Jaipur, India, 2008/2/9
OutlineOutline
• Physics Motivation • J/ suppression at RHIC• Hydro+J/ model• Determination of J/ melting temperature • J/ suppression in Hot-wind• Calculation of J/ v2 • Future plan – forward rapidity • Summary
Evaluated from J/ production in d+Au collisions. A.Adare et al. (PHENIX) arXiv:0711.3917
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Au+Au: A. Adare et al. (PHENIX) PRL 98 232301 (2007)Cu+Cu: A. Adare et al. (PHENIX) arXiv:0801.0220
Au+Au (|y|<0.35)
Au+Au (1.2<|y|<2.2)
Cu+Cu (|y|<0.35)
Cu+Cu (1.2<|y|<2.2)
•J/ suppression at mid-rapidity at RHIC is compatible to CNM effects except most central Au+Au collisions.•Stronger suppression at forward rapidity than CNM effects.
J/J/ Suppression at RHIC Suppression at RHIC• Two proposed scenarios:
– Gluon dissociation + recombination• Dissociation by thermal gluons supplemented by the regeneration
of J/ from ccbar coalescence – R. Rapp et al. [EPJC34, 91 (2005), arXiv:0712.2407], L. Yan et al. [PRL97,232301 (2006)], R. Thews [NPA783 301(2007)],A.Andronic et al.[nucl-th/0701079], etc– Need to take into account charm production and its modification in t
he medium, which are still unclear at RHIC.
– Sequential Melting of J/• Absence of the feed down J/ from c and ’ (30-40%) just above
Tc and melt of direct produced J/.– F. Karsch et al., PLB 637 (2006) 75 – Feed down fraction is unclear at RHIC (<~40% 90%CL).– This is still in a qualitative level and need to take into account the s
pace-time evolution to study dynamically.
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Hydro+J/Hydro+J/ model model
• First attempt for the study of sequential suppression of charmonia at RHIC.– Incorporate J/, c and ’ into the evolution of matter.
• Evolution of matter : (3+1)-dimentional relativistic hydrodynamics – T. Hirano and Y. Nara, PRL 91, 082301, (2003)– T. Hirano and Y. Nara, PRC 69, 034908, (2003)– T. Hirano and K. Tsuda, PRC 66, 054905, (2002)– http://tkynt2.phys.s.u-tokyo.ac.jp/~hirano/parevo/parevo.html
• J/, c and ’ : impurity traversing through the matter– Assume three kinds of interaction inside QGP.
Modeling of J/Modeling of J/ suppression suppression
• Survival Prob. In the medium:
• Decay Width:
• Motion of J/: free streaming
• Total Survival Prob.
• Free Parameters:
– (TJ/, T, fFD )
0
))((exp)( /// dxTxS JdisJJ
J/x0
(pT)
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0// )( xx JJ
,// )1( SfSfS FDJFDtotJ
• x0(Production point) is distributed according to the spatial Ncol distribution.• pT is distributed according tothe measured J/ distribution.• J/ azimuthal angle, , is flat (0 to 2).
)()1/(),()( /3
/ JcJdis TTTTTTT T. Song, Y. Park and S. H. Lee Phys.Lett.B659:621-627,2008.
Model resultsModel results
• Best Fit @ (TJ/, T, fFD) = (2.00Tc, 1.34Tc, 10%)
Bar: uncorrelated sys.Bracket: correlated sys.
• Onset of J/ suppression at Npart ~ 160.( Highest T at Npart~160 reaches to 2.0Tc.)• Gradual decrease of SJ/
tot above Npart~160 reflects transverse area with T>TJ/ increases.• TJ/can be determined in a narrow region.
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)(CNMRRS
AA
AAAA
Contour map
1
2
Decay width below TDecay width below TJ/J/
• Decay width :
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T. Song, Y. Park and S. H. Lee Phys.Lett.B659:621-627,2008.
)()1/(),()( /3
/ JcJdis TTTTTTT
• Suppression pattern is similar up to < 0.2. (T=2Tc)<~0.2 GeV
Hot-wind scenario Hot-wind scenario
• Melting temperature depends on the relative velocity between J/ and fluid.
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4/12 )1)(0()( vTvT meltmelt H. Liu, K. Rajagopal and U. A. Wiedemann : hep-ph/0607062.
(TJ/, T, FD) = (2.0Tc, 1.34Tc, 10%)
• Magnitude of the suppression in hotwind is similar to the free streaming case.• Gradual decrease above 50 is the effect of hot-wind. Next is SAA vs. pT! Free streaming Hot-
wind
pT dependence of SpT dependence of SAAAA 11
Free streaming Hot-wind
20-30%
0-10%
40-50% 50-60%
• pT dependence of the suppression is greatly different. • Suppression is flat in case of free streaming.• Suppression is stronger for high pT J/ in case of hot-wind as predicted.• Critical pT in hot-wind relates to the achieved temperature in fluid.
• v2 is small (<1%) in case of free streaming.• v2 is larger for higher pT J/ in case of hot-wind (~3% v2).
• v2 increases above critical pT.
Thermalization ScenarioThermalization Scenario• Assume that J/ flows in the fluid (T>Tfo).
– J/ moves according to fluid velocity (T>Tfo) and freeze-out at Tfo. Momentum of J/ is distributed according to Boltzman eq. Then boost J/ according to fluid velocity.
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10-20%0-10%
20-30% 40-50%
v2 = 30%
Tfo = 1.0Tc
• v2 is much larger than that of free streaming and hot-wind case.•Large v2 is predicted in low-mid pT since most of J/in low-mid pT are followed by flow of the fluid. •Magnitude is similar to the case of coalescence model. But tendency is much different for high pT.
ThermalizationFree streaming Hot-wind
v2 = 30%
Future plan – forward Future plan – forward rapidity rapidity
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• Stronger suppression at forward rapidity : CGC? (M. Nardi’s talk Session VI)• Further studies will be done in conjunction with CGC.
SummarySummary• J/ suppression at RHIC was investigated using hydro+J/ mo
del.– Dynamical and quantitative approach to the sequential suppression.
• Comparison of the experimental survival probability shows:– Observed suppression is described well with TJ/~2.0Tc at mid-rapidity a
nd TJ/ can be determined in a narrow region. – Decay width seems to be (T=2Tc)<0.2 GeV.
• Hot-wind calculation was done in this model.– Large suppression and ~3% v2 in high pT region can be seen in a scenar
io with hot-wind. High pT J/psi is important for this model.– Critical pT depends on the achieved temperature in the fluid.
• Thermalization scenario shows :– larger v2 (10-30%) in low-mid pT region (pT<4 GeV) and small v2 (<5%) i
n high pT region. Much different from other scenarios. • Further studies of stronger suppression in forward rapidity will b
e done in conjunction with CGC. Effect of recombination will be studied.
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Back Up SlidesBack Up Slides
Feeze-out Temp. DependenceFeeze-out Temp. Dependence• Assume that “survived” J/ flows in the fluid.
– J/ moves according to fluid (T>Tfo) and freeze-out at Tfo. Momentum of J/ is distributed according to Boltzman eq.
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10-20%0-10%
20-30% 40-50%
v2 = 30% Tfo = 1.0TcTfo = 1.1TcTfo = 1.2Tc
• Most of low-mid pT J/y is from flowed J/y. • Large v2 is predicted due to the flow of fluid. • It depends on the freeze-out temp. of J/y.• Magnitude is similar in case of coalescence model. But tendency is Much different.
Hot-wind in hydro+J/Hot-wind in hydro+J/ model modelT. Gunji, H. Hamagaki, T. Hatsuda, T. Hirano, Y. Akamatsu : Phys. Rev. C 76:051901 (R), 2007 Parallel talk at QM2008 by T. Gunji , Feb. 9th SessionXVIII 15:20~15:40
1: Survival Probability of J/ vs. Npart 20-30%Npart ~ 170
H. Liu et al. PRL.98:182301,2007
•J/ suppression from Hot-wind scenario was calculated in hydro+J/model.•Overall suppression pattern is similar in both cases. •Larger suppression and large v2 (~3%) in the high pT region in a scenario with hot-wind.