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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. Two extremely different dynamical scenarios Claim to account for AA p T quenching Opaque QCD plasma leads to quenching
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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
Two extremely different dynamical scenarios Claim to account for AA pT quenching • Opaque QCD plasma leads to quenching and strong collective flow: => AA provides info on equation of state • Transparent matter = No final state interactions But strong initial Wave function distortions CGC => eRHIC will provide precision measurements AA RHIC Impass
SPS – “Cronin” effect RHIC–“Jet Quenching” PHENIX Pion Quenching at 200 AGeV D. d’Enterria QM02 PHENIX Preliminary binary scaling
The most powerful Probe of the QCD Equation of state: Mh dependence v2 • Jet Tomography via pions indicates that very high density Matter was formed in Au+Au at 200 AGeV • High pTElliptic Flow consistent with highly opaque matter • Kolb et al, Teany et al: Hydrodynamics of “soft” pT<2 GeV matter • See R. Snellings • for puzzling E dependence
Three Competing Nuclear Effects In A+A at RHIC • Nuclear Wavefunction • pQCD: quark shadow, EMC; glue (anti?) shadow • CGC : Saturated glue xGA< c Q2 R2 < A xGp • Initial State Interactions (Cronin) • Glauber multiple collisions (target frame) • None in CGC* (*KLMc flavor) • Final state Interactions • dEg/dx , l • None in CGC*
What is the Nuclear Parton Wave function? EKS anti-shadow? eA info on quark shadow HIJING Q2 indep Super Deep shadow ? What is CGC* prediction in 0.01< x < 0.1??
Cronin Initial State Interactions Alberto Accardi Ivan Vitev, MG, PRL89 (02) Dumitru, Jalilian-Marian, Gelis
Canonical Glauber Multiple Collision Accardi, Treleani; GLV ; Wang Kopeliovics et al; Dumitru,Gelis, Jalilian-Marian Color Dipole Scattering
Non-abelian Radiative Energy Loss “Thick” Plasma Limit “Thin” Plasma Limit QCD Bethe-Heitler QGP Multiple Collision Ivan Vitev NPB 595
Quenched pQCD Hadron Spectrum Intrinsic kT + Nuclear Cronin EKS98 shadow/EMC SA GRV98 pdf BKK ff P(e) from GLV GVW: PRL86(01)2537 to include medium induced energy loss geometry
Single Hadron Tomography from SPS, RHIC, LHC Ivan Vitev and M.G, Phys.Rev.Lett. 89 (2002) Cronin dominates at SPS Cronin+Quench+Shadow conspire to give ~ flat R~Npart/Nbin at RHIC dNg/dy ~ 1000 -> g ~100 0 Predicts sub Npart quench, positive pT slope of R at LHC and RLHC(40)~RRHIC(40)
Color Glass Model(KLMc flavor) Claim no initial nor final state interaction can explain quenching of charged pi+K+p due to saturation ! PHENIX AuAu(10%) => hch
KLMc version of CGC Using gg g GLR formula
GLR with Classical Yang Mills Teaser Q/L=5
CGC dNg~1/pT4 tail and RHIC pQCD (GRV,K=2,BKK) Large phenomenological modifications of CGC/GLR Needed at RHIC because Asymptotic Log1/x >>1, Log Qs/ conditions are not reached at RHIC 0.01< x <0.1
RHIC x>0.01 Large phenomenological Modifications of CGC formulas required 1) 2) 3) Neglect of q ~ g contributions, renormalize 4) Ignore baryon anomaly and different quenching of pions
d+Au essential to test which physical approximation to Initial State Physics is closer to reality This is the well learned lesson from J/Psi at SPS
Gluon Shadow Jet Quenching BRAHMS PRL88(02) XN Wang, MG No Cronin P0=2GeV
Shadow vs Cronin in d+Au : X.N. Wang Cronin only Old HIJING1… shadow New HIJING2… shadow
Ivan Vitev 03 Cronin systematics in D+Au at 200 AGeV Centrality Dependence Rapidity Dependence
Prediction of KLMc version of CGC for d+Au GLR
Summary • Two extreme opposite interpretations of RHIC AA data exists • Evidence for opaque 100 x nuclear density matter • 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 , then interpretation (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 , then interpretation (2) and AA= shattered color glass No QGP matter => go to eRHIC to map xGA. • IF 0.7< R(5 GeV) < 1 ??? Back to the drawing board ???