Quark Matter 2005, Budapest

Xin-Nian WangLawrence Berkeley National Laboratory

Jet and Leading Hadron Production

• Asymptotic freedom

• Scale anomaly

• Phase transition

Asymptotic Freedom and QCD

22 2 23

4( )

(11 ) ln( / )sf QCD

Qn Q

412

sa aT F F B

1/ 40.72cT B

David J. Gross H. David PolitzerFrank WilczekNobel Prize in Physics 2004

Hard processes in heavy-ion collisions

q

q

leadingparticle

leading particle

pQCD

H. Zhang,J. Owens, E. Wang XNW, in preparation

Before the Beginning…

Single Spectra Suppression

XNW and M. GyulassyPhys. Rev. Lett. 68, 1480 (1992)

ET

PHENIX

Non-suppression in p+A

XNW, Phys. Rev. C 61, 064910 (2000) [hep-ph/9812021]

PHENIX

Azimuthal Anisotropy

XNW Phys. Rev. C 63, 054902 (2001)Gyulassy, Vitev & XNW Phys. Rev. Lett. 86, 2537 (2001)

STAR

Suppression of Back-side Correlation

Pedestal&flow subtracted

STAR, Phys. Rev. Lett. 90, 082302 (2003)

Modified Fragmentation

2 ( , ) 21( , ) (virtual)

(1 ) ( )

Aqg L A S

L Aq c

T x x Czz x

z f x N

Guo & XNW’00

( )( ) ( ) ( )D zz DD z D z

2 122

40

( , ) ( , )2

h

Q

S hq h h L q h

z

zd dzD z Q z x D

z z

DGLAP-like

Parton Energy Loss and QGP

2 111 2 2 1 1), ) ( )( ( L LA ix p y ix

gp

Ly

qT x x dy F ydy eF ey

Gluon density correlation:

0

320( )(

2ln)a

R

A s

EE C C d

BDPM; Gyulassy Vitev LevaiWang & XNW; Wiedemann; Zakharov

LPM interference

pQCD Analysis of Jet Quenching

2 2 2 2 21 2 1 22

( ) ( )ABA B a a b b

abcdT

dK d b d rd r t r t r dx d k dx d k

dyd p

/ // 1 2( , , ) ( , , )1

( )aa A a a

b ch

db b cb B c

c

f x k r f xdt z

k zd

Dr

Parton distr. in nuclei & pT broadening Modified Frag. Fun.

E. Wang & XNW (2002), XNW (2004)Gyulassy, Levai & Vitev (2002)Eskola, Honkanen, Salgado & Wiedemann (2005)Q. Wang & XNW (2005)Turbide, Gale, Jeon & Moore (2005)Dainese, Loizides & Paic (2005)…

Jet Quenching at RHIC

0

13.8 3.9 GeV/fmdE

dx cold matter

0.5 GeV/fmdE

dx

0

320( )(

2ln)a

R

A s

EE C C d

30( ) 30 fm

XNW, PLB595(04)165.

LO analysis,

Energy Dependence of Jet Quenching

D. d’Enterria, Hard Probes 2004

63 GeV

XNW, PLB579(2004)299

Effect of non-Abelian energy loss

Eg=Eq

Eg=2Eq

Q. Wang & XNW nucl-th/0410079

Effects in heavy/light hadron ratio– Armesto, parallel 3c

pT=6 GeV

q=0.9 0.1

EskolaHonkanenSalgadoWiedemann

Nuclear Size Dependence

0

320( )(

2ln)a

R

A s

EE C C d

Sensitivity of RAA

•Cronin effect

•Slope of the jetspectra

•E-dependence ofthe energy loss

Gyulassy & VitevEskola,HonkanenSalgado,Wiedemann

Back-2-back Dihadron Correlations

Pedestal&flow subtracted

/( )

/

( ) ( )

( )

asso trigtrig T T

AA T T trigT

trig assoT T

TT T T

trigT

TT T

d dp dpD z p

d dp

d p pdE D D

dE E E

d pdE D

dE E

ET

= STAR preliminaryMajestero

XNW, PLB595(04)165.

Modified Dihadron Fragmentation

h1h2

h1h2

h1

h2

1 2 1 2 1 2 1 2( , ) 0 (0) , , ( ) 02q h h q h h h h q

S

D z z Tr p p S p p S y

h1

h2

jet

Majumder & XNW’04,05Majumder, parallel 3b

Modified Dihadron Fragmentation

D(z1,z2)/D(z1)Triggering h1

Hermes Preliminary

Majumder & XNW nucl-th/0412061 E. Wang & XNW, PRL89 (2002) 162301

Pedestal&flow subtracted

Majumder, parallel 3b

Soft hadrons rings

PHENIX

Stoecker’04Casalderrey-Solana,Shuryak & Teaney ‘04Casalderrey-Solana (parallel 3b)

M

1cos M

sc

Shock wave?

LPM & Angular Correlation

2

2 2

1 (1 ) 1

2g S

FT T

dN zC

dzdk z k

Radiation in vacuum

2

2 4

11 f

R

g

T T

dNe

dzdk k

2

2 (1 )f

T

Ez z

k

Formationtime

[ , ]Tk kMultiple Scattering in QCD

max

2

gR

LPM & Cherenkov-like Bremsstrahlung

2

2 2 2

11

[ (1 ) ( )]f

R

g

T T

dNe

dzdk k z k

2

2 (1 )

(1 ) ( )fT

Ez z

k z k

J. Ruppert & B. Muller PLB619(2005)123.Dremin, JETP(1979), hep-ph/0507167Dremin (parallel 10a)

2 20 ( ), Re ( ) 0k k k k

Majumder & XNW nuth-0507063

2 1cos

( )c

zz

k

2

max (1 ) ( )Tk z k 20( ) 1 ( ) /k k k Dielectric constant

Resonances in QGP above Tc?

J/survives at T=1.6-2 Tc

Asakawa &Hatsuda ’04S. Datta, et al ‘04

F. Karsch & Laermann ‘03

Could there be other resonances?

Shuryak & Zahed ‘04

Lee, Mocsy (parallel 10c); Mannarelli, Petreczky (parallel 7a)

Dielectric Constant in QGP

Strong p-dependence Cherenkov angle

Koch, Majumder & XNW’05See Majumder (parallel 3b)

1cos

( )c

p

Future of Jet Quenching I

• No-trigger bias– Initial energy

– Surface emission

– Correlation background due to v2

XNW, Huang & Sarcevic,PRL77(96)231-jet Events

Future of Jet Quenching II

• Heavy quark jet quenching– Djordjevic, Rapp, Teaney (parallel 5b)

– B. Zhang (parallel 5a)

• Parton recombination at intermediate pt– Ko (parallel 2b), Hwa (parallel 3a),

E. Wang (parallel 3c)

• 3D jet tomography– Adil (parallel 3a)

• Incorporate dynamic evolution of bulk matter

Summary

• Discovery of Jet Quenching at RHIC proves that a interacting dense matter is formed: Opaque to jets

• Dense matter at RHIC is 30 times higher than cold nuclei, energy density is 100 times higher

• Jet tomography a useful and power tool for studying properties of dense matter– Heavy quarks, dihadron correlation, angular

distribution, flavor dependence …

• Soft hadron correlation Cherenkov radiation dielectric property of the QGP at RHIC

Back-up I

Jet Quenching Tomography