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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
2
Physics MotivationPhysics Motivation• Quark-Gluon-Plasma (QGP)
– New state of QCD matter expected to be created at high temperature (Tc = 160-190MeV).
• Quarkonia suppression in QGP– Color Debye Screening
• T.Matsui & H. Satz PLB178 416 (1986)
– Suppression depends on temperature (density) and radius of QQbar system.
• TJ/ : 1.6Tc~2.0Tc • T, T’ : ~ 1.1Tc
– Serve as the thermometer in QGP.
Color Screening
cc
3
M.Asakawa and T.Hatsuda, PRL. 92, 012001 (2004)A. Jakovac et al. PRD 75, 014506 (2007)G.Aarts et al. arXiv:0705.2198 [hep-lat]. (Full QCD)
J/J/ Suppression at RHIC Suppression at RHIC• J/ suppression in A+A Collisions at RHIC
(dN/dy)AuAu
(dN/dy)pp x<Ncol> RAA =
CNM effects • Gluons shadowing • Nuclear absorption
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.
5
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.
» Free Streaming » Hot-Wind » Complete Thermalization
6
T. Gunji et al. Phys. Rev. C 76:051901 (R), 2007
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)
7
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.
8
)(CNMRRS
AA
AAAA
Contour map
1
2
Decay width below TDecay width below TJ/J/
• Decay width :
9
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.
(TJ/, T, FD) = (2.0Tc, 1.34Tc, 10%)
Calculation of J/Calculation of J/ v2 v212
Free streaming Hot-wind(TJ/, T, FD) = (2.0Tc, 1.34Tc, 10%)
20-30%0-10%
40-50% 50-60%
v2 = 3%
v2 = 3%
• 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.
13
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
14
• 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.
15
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.
18
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.
RAA
(1.2<|y|<2.2) /RAA
(|y|<0.35)
1
RAA
0
1
0
Bar: uncorrelated errorBracket : correlated error
Forward rapidityForward rapidity• Stronger suppressionat forward rapidity.
– Gluon saturation (CGC)?• Leading to suppression of charm production
25
=2
Open charm yield in Au+Au @ 200 GeV
=0 ~60% Suppression patterndue to CGC
K. L. Tuchin hep-ph/0402298
(TJ/,T) = (2.02Tc,1.22Tc)FD = 30% (y=0), FD= (35-50)% (y=2)
Forward RapidityForward Rapidity• Experimental SJ/
tot (y=2)– CNM at y=0 & CGC suppression (y=2/y=0)
• Model SJ/tot (y=2)
– Hydro at y=2
• Need larger feed-down fraction at y=2.• Onset of suppression at Npart ~ 240?
• 2.02Tc is achieved at Npart~240 at y=2?
Further analysis is on going.
26
SJ/(y=0)=RAA/CNM(y=0,abs=1mb)
SJ/(y=2)=RAA/R(CGC)/CNM(y=0,abs=1mb)
c feed-down fraction
Feed down fractionFeed down fraction• Feed down fraction
– ~40% of J/ from c and ’
34
χ,1,2 J/ ~30%
΄ J/ 5.5%
Complete ThermalizationComplete Thermalization• T>Tc: J/ moves according to fluid velocity vecto
r.• T~Tc: J/ freeze-out:
– Re-arrange the J/ px, py and pz using Boltzman Eq (in local fluid coordinate).
– Then boost J/ according to the fluid velocity vector.
322
)exp( pdTc
pmN
22
pT and v2 of flowed J/pT and v2 of flowed J/• J/ participating in the flow of the matter
dN/dpT [A.U] v2
23
Melting temperatureMelting temperature• Spectral analysis in quenched lattice.
J/ c
J/ c
Datta, Karsch, Petreczky & Wetzorke, hep-lat/0312037
Asakawa & Hatsuda, hep-lat/0308034
Tc~270 MeV
J/ may survive up to ~2Tc. c and y’ would melt at ~1Tc.
T. Hatsuda QM2006 (hep-ph/0702293)
27
Melting temperatureMelting temperature• Spectral analysis in full lattice (Nf=2).
T. Hatsuda QM2006 (hep-ph/0702293)
28
Jc
Aarts et al., hep-lat/0610065
Even with the light quarks, J/ may survive up to ~2Tc.
Tc~170 MeV
pT [GeV]
Hydro. calculationHydro. calculation• (3+1) dimensional hydro. (,x,y,s)
– r, T, v(vx,vy) at (,x,y,s) 0 = 0.6 fm/c, Tc=170 MeV– Massless parton gas (u,d,s,g)– Tuned to reproduce dN/dh
31
Hydro data are open to public:http://tkynt2.phys.s.u-tokyo.ac.jp/~hirano/parevo/parevo.html
T.Hirano and Y.Nara, PRL91,082301(2003);T.Hirano and Y. Nara PRC69,034908(2004);T.Hirano and K.Tsuda, PRC66,054905(2002).
Hydro+Jet modelHydro+Jet model• Hydro+“hard probe” works.
– Identified hadron spectrum
– Back-to-back correlation
– Pseudo-y dependence of RAA
32
T. Hirano and Y. Nara PRL91 082301 (2003)
pT [GeV]
T. Hirano and Y. Nara PRC69 034908 (2004)
T. Hirano and Y. Nara PRC68 064902 (2003)
TTJ/J/ comparison comparison• This study shows TJ/~2.02Tc.
• Estimation of TJ/ in 3-falvor QCD from quenched lattice QCD.
3
/4/1
3
/
368/716
16f
f
Nc
qc
qc
J
Nc
J
T
T
T
T
T
T
33
= 1.7 = 270/170Asakawa & Hatsuda, hep-lat/0308034
This coincides with the resultobtained in this study.
05.23
/
fNc
J
T
T
Map of SuppressionMap of Suppression• Example of suppression map
– 10-20% centrality, Tmelt = 1.0Tc Production probability map
Temperature Field (=0.6 fm/c)
Suppression Map(integrated over )
Similar to surface emission! Main component of survival J/psi
Small component (gained by large Ncoll )
9
Sensitivity for TSensitivity for TJ/J/& FD& FD
• TJ//Tc = 1.88, 1.94,
2.00, 2.06, 2.12
9
TJ/y can be determined in a narrow region around 2.00Tc.
Forward-RapidityForward-Rapidity• Use hydro at y=2
– (TJ/y, T, FD) free• (2.08Tc, 1.62Tc, 70%)• Chi2 = 0.83
– (TJ/y, T) fixed• (TJ/y, T) = (2.0, 1.34)
• FD45%, chi2 = 10
15
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
Melting temperatures : (TJ/, T) = (2.0Tc, 1.34Tc) 10% feed-down correction
4/12 )1)(0()( vTvT meltmelt
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.
2: Survival Probability of J/ vs. pT
3: v2 of J/ vs. pT
Melting temperature in hot-wind
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