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Why the current Deuteron+Au data from RHIC are critical to decide if a QGP was formed in

Au+Au

M. Gyulassy: BNL 3/8/03, LBNL 12/17/02

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AA RHIC Impass

Two extremely different dynamical scenarios Claim to account for AA pT quenching

1. Opaque QCD plasma leads to quenching and strong collective flow:=> AA provides info on equation of state

2. Transparent matter = No final state interactions But strong initial Wave function distortions CGC

=> eRHIC will provide precision measurements

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Pion Quenching at 200 AGeV

)

) (inelastic

ppT pp

2binary

TAA 2

eventsT AA

/ d /dp (d N

d /dp N d 1/Np R

PHENIX Preliminary

D. d’Enterria QM02

binary scaling

PHENIX

SPS – “Cronin” effect

RHIC – “Jet Quenching”

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• Jet Tomography via pions indicates that very high densityMatter was formed in Au+Au at 200 AGeV

• High pT Elliptic Flow consistent with highly opaque matter

The most powerfulProbe of the QCDEquation of state:

Mh dependence v2

• Kolb et al, Teany et al: Hydrodynamics of “soft” pT<2 GeV matter

•See R. Snellingsfor puzzling E dependence

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1. Nuclear Wavefunction a) pQCD: quark shadow, EMC; glue (anti?) shadow b) CGC : Saturated glue xGA< c Q2 R2 < A xGp

2. Initial State Interactions (Cronin)a) Glauber multiple collisions (target frame)b) None in CGC* (*KLMc flavor)

3. Final state Interactions a) dEg/dx , b) None in CGC*

Three Competing Nuclear EffectsIn A+A at RHIC

a/A a/pf (x,Q) A f (x,Q)¹

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What is CGC* prediction in 0.01< x < 0.1??

eA info on quark shadow EKS anti-shadow?

HIJING Q2 indepSuper Deep shadow ?

What is the Nuclear Parton Wave function?

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Cronin Initial State Interactions

Ivan Vitev, MG, PRL89 (02)

Alberto Accardi

Dumitru, Jalilian-Marian, Gelis

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Accardi, Treleani; GLV ; Wang

Kopeliovics et al; Dumitru,Gelis, Jalilian-Marian

Canonical Glauber Multiple Collision

Color Dipole Scattering

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QCD Bethe-Heitler

QGP Multiple Collision

Non-abelian Radiative Energy Loss

2 2

Lc 5fm

q Lc 2

E E 10GeV

E 60GeV

“Thick” Plasma Limit

Ivan Vitev NPB 595

gL / OpacityExpansion

“Thin” Plasma Limit

(1 x)ExE

g(1) 3s R 22

dN1L( )

R dy9

E CL

L4

2Eog

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to include medium induced energy loss

222 2 log(1 )

5^

^ ^= + +

pA pp

pk k L

ml

Intrinsic kT + Nuclear Cronin

EKS98 shadow/EMC SA

GRV98 pdf BKK ff

P() from GLV

GVW: PRL86(01)2537

geometry

Quenched pQCD Hadron Spectrum

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Single Hadron Tomography from SPS, RHIC, LHC

1. Cronin dominates at SPS

2. Cronin+Quench+Shadow

conspire to give ~ flat

R~Npart/Nbin at RHIC

dNg/dy ~ 1000 -> g ~100 0

3. Predicts sub Npart quench,

positive pT slope of R at LHC

and RLHC(40)~RRHIC(40)

Ivan Vitev and M.G, Phys.Rev.Lett. 89 (2002)

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Color Glass Model (KLMc flavor)

PHENIXAuAu(10%)=> hch

Claim no initial nor final state interaction canexplain quenching of charged pi+K+p due to saturation !

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Using gg g GLR formula

KLMc version of CGC

BNL 3/6/03 Gyulassy 150 5 10 15 20

0.0001

0.001

0.01

0.1

1

10

5 10 15 20

0.85

0.9

0.95

1.05

1.1

GLR with Classical Yang Mills

dNdyd2 k

µà0

1L dzz3

J0@kzDik1- ã14I-z2MQ2 LogB1Hz LL2Fy{2

k/Q

21/k

41/k

Q/

Teaser

BGdN / dN

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CGC dNg~1/pT4 tail and RHIC

p GeV^

2

dNdydp

p

^

pQCD (GRV,K=2,BKK)

g q g

CYM BKK+ ® p

0p 2=

0p 6=

CYM BKKpQCD(GRV BKK)

+ ®+ ®

pp

0p 2=

0p 6=

Large phenomenological modifications of CGC/GLRNeeded at RHIC because

Asymptotic Log1/x >>1, Log Qs/conditions are not reached at RHIC 0.01< x <0.1

p GeV^

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RHIC x>0.01 Large phenomenologicalModifications of CGC formulas required

2 2 2 2s s

4(x,p ) (p / Q (x)) (p / Q (x))(1 x)

s

2 2

0.3 0.52s

22

s42

s (1Q (x)

p(p /Q (x)) (p / )) x)Q (x

3) Neglect of q ~ g contributions, renormalize K

1)

2)

4) Ignore baryon anomaly and different quenching of pions

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d+Au essential to testwhich physical approximation

to Initial State Physics is closer to reality

This is the well learned lesson from J/Psi at SPS

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Jet Quenching

XN Wang, MG

Gluon Shadow

P0=2GeVBRAHMSPRL88(02)

No Cronin

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Shadow vs Cronin in d+Au : X.N. Wang

Old HIJING1… shadow

New HIJING2… shadow

Cronin only

dAuR (p )

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Ivan Vitev 03

Centrality Dependence Rapidity Dependence

Cronin systematics in D+Au at 200 AGeV

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GLR

Prediction of KLMc version of CGCfor d+Au

d Au Au AuR R 0.5 0.7

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Ivan Vitev 03

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Summary• Two extreme opposite interpretations of RHIC AA data exists

1. Evidence for opaque 100 x nuclear density matter2. Evidence for deep gluon shadowing (saturation)

• Ambiguity due to competition between initial nuclear wavefunction Shadowing, initial state (Cronin) interactions, and final state int.

as pointed out in 1992 p+A (or d+A) needed to isolate Initial State effects : shadowing and Cronin

• IF RHIC finds R(5 GeV) ~ 1.1-1.3 in d+Au , theninterpretation (1) QGP matter was produced in AA And RHIC AA Has chance to map out QCD EOS

• IF RHIC finds R(5 GeV)< 0.7 in d+Au , theninterpretation (2) and AA= shattered color glassNo QGP matter => go to eRHIC to map xGA.

• IF 0.7< R(5 GeV) < 1 ??? Back to the drawing board ???

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Phys.Rev.Lett.77 (96) 1222