J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ.,...

66
J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J. Xu, arXiv:1008.2730

Transcript of J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ.,...

Page 1: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

J/ψ production and elliptic flow in relativistic heavy-ion

collisions

Taesoo Song(Texas A&M Univ., USA)

Reference : T. Song, C. M. Ko, S. H. Lee and J. Xu, arXiv:1008.2730

Page 2: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Contents

1. Introduction2. Schematic model for fireball

expansion3. Thermal properties of charmonia 4. Charmonia in heavy-ion collisions5. Results6. Summary

Page 3: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

1. introduction

Page 4: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

QCD phase diagram

Page 5: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

• Long time ago, J/ψ suppression was suggested by Matsui and Satz as a signature of QGP formation in heavy-ion collisions. (due to color screening between c and anti-c)

• The suppression was observed at SPS & RHIC.• LQCD suggests the dissociation temperature

of J/ψ higher than Tc.• J/ψ is still one of the promising diagnostic

probes for hot nuclear matter created by heavy-ion collisions.

J/ψ suppression

Page 6: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Phenomenological models

1. Statistical model (P. Braun-Munzinger)Low dissociation temperature of J/ψ Most J/ψ in heavy-on collisions are

regenerated ones.

2. Two-component model (R. Rapp)High dissociation temperature of J/ψ Some of J/ψ come from regeneration, some

of them come from initial production.

Page 7: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

NJ/ψ vs. Npart

statistical model two-component model

Page 8: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

NJ/ψ vs. Pt

statistical model two-component model

Page 9: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Questions

• How can both models successfully describe experimental data?

• How can both models be discriminated?

Page 10: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

2. Schematic model for expanding fireball

• Initial condition• Equation of state (EoS)• modeling

Page 11: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

2. 1. Glauber model

function. thickness; ),()(

ondistributiSaxon - Woods; e1

(r) where

),( ),( )(

collisionsbinary ofNumber 2.

)(1 1 )(

)(1 1 )()(

tsparticipan ofNumber 1.

,,

/)r-(r0

2

2

2

0

dxxbbT

zsbzszsdzddbN

sdsTsbTB

sdsbTsTAbN

BABA

C

BAincoll

AinAB

B

inBApart

b

s b-s

Page 12: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

2. 2. Initial condition

GeV 200 at 11.0

GeV 130 at 09.0

2)1(

NN

NN

collpart

ppch

BAch

sx

sx

xNN

xd

dN

d

dN

Charged particle multiplicities PRC65, 061901 (2002) dAdNndAdNn

xnn

xV

Ss

collcollpartpart

collpart

00 / ,/ where

,2

)1(3.30

be toassumed is

stage initialin density entropy Local

Page 13: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

EoS of QGP• Quasiparticle picture

Strongly interacting massless partons

Noninteracting massive partons to reproduce thermal quantities extracted from LQCD

05.1/ ,170 ,3

, 14.18

18),,(

,),,(ln)211(

48)( where

, 3

)( ,

632

)(

2)/(5.0

2

22

222

222

ccf

c

cTTc

cfc

qfc

g

TMeVTN

T

T

T

eTTF

TTFNNTg

TTgm

NNTTgm

C

P. Levai & U. Heinz PRC 57, 1879

(1998)

Page 14: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

EoS of HG

• Resonance gas model 1. all mesons of masses lighter than

1.5 GeV & all baryons of masses lighter than 2.0 GeV are considered in HG phase.

2. They are assumed to have constant masses and to be noninteracting.

Page 15: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Energy density and pressure

0.15 0.20 0.25 0.30 0.350

4

8

12

16

e/T4

p/T4

e/T

4 , p/T

4

T (GeV)

)(

1

1

23

1)(

)(

12

)(

/22

23

/

223

22

22

TBepm

ppdTp

TB

e

pmpdT

Tpm

Tpm

Page 16: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Isothermal lines on transverse plane at τ0=0.6 fm/c

Page 17: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Temperature profiles at various impact parameters

Page 18: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

2. 3. fireball expansion

• Radial acceleration in central collision

24.1

2

36.0mass inertia :

~area lcylindrica :

out-freezeat pressure :

)(

part

f

fr

NM

RA

pM

Appa

Parameterized to fit

experimental data <pt> of π, K, p at freeze-out

Page 19: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

0 5 10 15 200.1

0.2

0.3

0.4

T (

GeV

)

t (fm/c)

0.2

0.4

0.6

0.8

v T (

c)

Assuming isentropic expansion, s(τ)=s0*v0/V(τ)

Page 20: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

• Radial acceleration in non-central collision

3

2

3

22/1

2

2

2

2 sincos)()v( ,

sincos)(

shape, ellipticin expanding Fireball

2.2z , ,1

1

y

y

x

x

yx

xy

xyry

rx

R

v

R

vR

RRR

RR

RRzaa

zaa

Parameter to fit

experimental data v2 of π, K, p at freeze-out

Page 21: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

0 2 4 6 8 10 12

4

6

8

10

Ry

Rx

Mixed

HGQGP

Rx,

Ry

(fm

)

(fm/c)

0.2

0.4

0.6

vy

v x, v

y (c

) vx

0.1

0.2

0.3

T (

GeV

)b=9 fm,

Page 22: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Blast wave model

TT

TpT

p

TT

TTT

T

T

TTT

T

pdyddN

pd

pdyddN

pd

v

dydpdN

dp

dydpdN

pdp

p

v

T

mK

T

pIrdrd

m

dydp

dN

22

22

2

22

22

1

1022

2cos

2cos

.tanh where

cosh

sinh

2

formula, Frye-Cooper usingby

Page 23: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

0 100 200 300 4000

200

400

600

800

1000

pions kaons protons

<p T

> (

MeV

/c)

Npart

0 1 2 3 4

0

10

20

30

pT (GeV/c)

v 2 (%

)

0

10

20

30

pions kaons protons

baryonfor 3 meson,for 2

14.1 ,/exp

gmultiplyinafter (bottom)1

n

GeVcncpT

Page 24: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

3. Thermal properties of charmonia

• Dissociation temperatures • Dissociation cross section in QGP and

in HG

Page 25: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

3. 1. wavefunctions & binding energies & radii of charmonia at

finite T

Modified Cornell potentialF. Karsch, M.T. Mehr, H. Satz, Z phys. C. 37, 617 (1988)

σ=0.192 GeV2 : string tension

α=0.471 : Coulomb-like potential constant

μ(T) =√(Nc/3+Nf/6) gT : screening mass in pQCD

In the limit μ(T)→0,

rTrT er

eT

TrV )()(1)(

),(

rrTrV

),(

Page 26: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Ψ’(2S)χc (1P)

GeVGeV

J/ψ (1S)

Screening mass

289 MeV298 MeV306 MeV315 MeV323 MeV332 MeV340 MeV

GeV

Page 27: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Binding energies & radii of charmonia

Screening mass (MeV)

Bin

ding

ene

rgy

(GeV

)

Screening mass (MeV)

Rad

ius

(fm

)

Page 28: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

3. 2. dissociation cross section

• Bethe-Salpeter amplitudeDefinition ;

Solution in NR limit ;

Page 29: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Leading Order (LO)

quark-induced Next to Leading Order (qNLO)

Page 30: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

gluon-induced Next to Leading Order (gNLO)

Page 31: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Leading Order (LO)

quark-induced Next to Leading Order (qNLO)

gluon-induced Next to Leading Order (gNLO)

Page 32: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

In QGP

σdiss= ∑j σ jpQCD

1. partons with thermal mass

2. temperature-dependent wavefunctions from modified Cornell potential are used.

In hadronic matterFactorization formula:

σdiss(p)= ∑ j ∫dx σ ipQCD (xp)Dj i(x)

Dj i(x) is PDF of parton i in hadron j interacting with charmonia

1. Massless partons

mass factorization, loop diagrams and renormalization remove collinear, infrared and UV divergence respectively

2. Coulomb wavefunctions are used.

Page 33: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

4. Charmonia in heavy-ion collisions

• Cronin effect• Nuclear absorption (nuclear

destruction)• Thermal decay and leakage effect• Regeneration

Page 34: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Two-component model

Initial production of J/ψ through binary N-N collisions

Thermalization (QGP formation)≈ 0.6 fm/c

HadronizationT≈ 170 MeV

Regenerated J/ψ Thermal decay

in hadronic matter

Thermal decay in QGP

Nuclear absorption

detector

Kinetic freeze-outT≈ 120 MeV

Thermal decay in hadronic matter

Cronin effect

Beforecc production

Page 35: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

4. 1. Cronin effect

1. Charmonia are produced mainly through g+g fusion

2. Different from in p+p collision, gluon in A+B collision can get additional Pt through g+N collision

3. It broadens Pt distribution of gluons

4. Subsequently, it broadens Pt distribution of J/ ψ in A+B collision, compared with in p+p collision

ABggN

gN

tpp

Jt

AB

Jt LP

PP

2

/

2

/

2

Page 36: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Primordial J/ψ is produced

Nucleus A

Nucleus B

Page 37: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

4. 2. Nuclear destruction

'

2

),()1(exp

),()1(exp

)',(),(')(

1),(

z

nucBBB

z

nucAAA

BAAB

nucnuc

zsbdzB

zsdzA

zsbzsdzsdzdbT

bS

Primordial J/ψ is produced

Nucleus A

Nucleus B

Nuclear destruction cross

section is obtained from pA

collisionσdiss=1.5mb

Page 38: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

4. 3. Thermal decay

J/ψ

QGP phase

Mixed phase(Assuming 1st order phase transition)

HG phase

J/ψ

J/ψ

Page 39: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Thermal decay widths in QGP & HG

phaseHG in )()(

phase mixedin )(*)1()(*)(

phase QGPin )()(

J/ ofsection crosson dissociati :

J/ and jbetween velocity relative :

J/ ngdissociatihardon or parton ofdensity :

)()(),()2( 3

3

HG

HGQGP

QGP

diss

rel

j

dissreljj

j

ff

v

n

TTvTnkd

g

Page 40: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Ψ’(2S)χc (1P)

J/ψ (1S)

Page 41: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

The leakage effect

Thermal decay width =0

Thermal decay width ≠0

Thermal decay width : Γ→Γ*θ[R(τ)-r(τ)]

Page 42: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Considering feed-down from χc , Ψ’ to J/ψ, '/ 08.025.067.0

HGQGPHGQGPJ

HGQGPHGQGP SSSS c

')'(exp0

dS HGQGP

Survival probability from thermal decay

Page 43: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

4. 4. Regeneration

• From Glauber model (dσccNN/dy=63.7(μb) from

pQCD),

• From Statistical model,

• Discrepancy between them is corrected with fugacity

• GCE is converted to CE because of small # of pairs

),(),()( 2BBBAAA

NNcc

ABcc zsbdzzsdzsdABbN

VnnN ChiddenopenABcc C

2

1

VnVnN ChiddenCopenABcc 2

2

1

VnVnI

VnIVnN hidden

open

openopen

ABcc C

2

C 0

C 1C ) (

) (

2

1

Canonical suppression

Page 44: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.
Page 45: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Relaxation factor for kinetic equilibrium

ionhadronizatat time the:

iparton by

charm-charm/anti ofsection cross scattering elastic :

iparton ofdensity number :

)/(1 timerelaxation where,

exp10 .

H

i

i

reli

iirelax

relax

n

vn

dR

H

Page 46: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

the number of regenerated J/ψ

NJ/ψrec=

VRγ2 {nJ/ψSJ/ψHG +Br(χc)*nχc *Sχc

HG + Br(ψ’) *nψ’* Sψ’HG }

• nJ/ψ, nχc , nψ’ : number densities of charmonia

• SJ/ψHG, Sχc

HG , Sψ’HG : survival rate of charmonia in HG

• Br(χc), Br(ψ’) : branching ratios of χc, ψ’ to J/ψ• R : relaxation factor• γ : fugacity

Page 47: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

5. Results

• RAA vs. Npart

• RAA vs. pT

• <pT>

• V2

• Higher-order corrections in pQCD

Page 48: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

5. 1. RAA of J/ψ

enhenced. is J/ 1, R

.suppressed is J/ 1, R

1

factoron modificatiNuclear

AA

AA

/

//

Jnn

JAA

coll

JAA N

N

NR

From RHIC near midrapidty at √sNN=200

GeV

Page 49: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

RAA of J/ψ as a function of Npart

(near midrapidity in Au+Au collision at √s=200

GeV)

Regeneration

Page 50: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

The role of coupling constant g in our model

1. ‘g’ determines dissociation temperatures of charmonia

(screening mass μ=√(Nc/3+Nf/6) gT) TJ/ψ=386 MeV, Tχc =199 MeV, TΨ’=185 MeV with

g=1.5

2. ‘g’ determines the thermal widths of charmonia (Г∼g2 in LO, and Г∼g4 in NLO)

3. ‘g’ determines the relaxation factor of charm quarks

Page 51: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

W/O initial dissociation of J/ψ

without

Page 52: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

RAA of J/ψ as a Function of pt

(For J/ψ, Tf=160 MeV)

Page 53: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

<Pt2> of J/ψ

Page 54: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

v2 of J/ψ (b=9 fm)

<Assumption>1. Elastic cross section

of J/ψ(color singlet) in QGP is much smaller than that of charm quark.

2. For J/ψ, inelastic collision is more effective than elastic collision in QGP because of its small binding energy and large radius at high T.

Page 55: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

RAA of J/ψ as a function of Npart

(near midrapidity in Cu+Cu collision at √s=200 GeV)

Regeneration

Page 56: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Applying to Pb+Pb collision at √sNN=5.5 TeV (LHC) with the modified

parameters• by extrapolation,

Entropy dS/dη= 30.3{(1-x)Npart/2+xNcoll}

to 78.5{(1-x)Npart/2+xNcoll}, where x=0.11

J/ψ production cross section per rapidity in p+p collision

dσJ/ψpp/dy= 0.774 μb to 6.4 μb

• from pQCD,

cc production cross section per rapidity in p+p collision

dσccpp/dy= 63.7 μb to 639 μb

Ref. is NPA 789, 334 (2007)

7.36 μb at 7 TeV (Nov. 2010)

Page 57: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

RAA of J/ψ as a function of Npart

(near midrapidity in Pb+Pb collision at √s=5.5 TeV)

Regeneration

Page 58: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

5. 2. Higher-order corrections

• Dissociation cross section of charmonia σ [J/ψ+q(g)→c+c+q(g)] *A ; enhances decay of charmonia

• Elastic cross section of charm quarks σ [c+q(g)→c+q(g)] *B ; enhances regeneration of charmonia

Page 59: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Fractions of regenerated J/ψ

=(A,B)

Page 60: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

RAA of J/ψ as a function of Npart

(near midrapidity in Au+Au collision at √s=200

GeV)

Page 61: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

RAA of J/ψ as a Function of pt

Page 62: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

<Pt2> of J/ψ

Page 63: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

v2 of J/ψ (b=9 fm)

Page 64: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

5. Summary

Page 65: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Summary of nuclear modification of charmonia in heavy-ion collision

• Before production; Cronin effect (pt↑)• After production; nuclear destruction (NJ/ψ↓) ; initial dissociation (NJ/ψ↓)• After thermalization; thermal decay (NJ/ψ↓); leakage effect (NJ/ψ↑, pt↑); regeneration (NJ/ψ↑); flow effect (pt↑)

Page 66: J/ψ production and elliptic flow in relativistic heavy-ion collisions Taesoo Song (Texas A&M Univ., USA) Reference : T. Song, C. M. Ko, S. H. Lee and J.

Summary of results

• We reproduced successfully RAA of J/ψ in Au+Au and Cu+Cu collisions at RHIC and estimated RAA in Pb+Pb collision at LHC by using 2-component model.

• There seems to be a kink in RAA vs. Npart curve in Au+Au collision. → initial temperature begins to be over TJ/ψ?

• 2-component model vs. statistical model The number of J/ψ : the excessive number of J/ψ in 2-component

model is reduced by multiplying relaxation factor to regenerated J/ψ.

pt of J/ψ : In 2-component model, Cronin effect mainly enhances pt while in the statistical model, flow effect mainly enhances.

→ both models successfully describe RAA and pt of J/ψ in RHIC.

• Only v2 of J/ψ seems to be able to discriminate two models. → Precise measurement of v2 of J/ψ will reveal the fraction of

regenerated J/ψ