# Presentation: 517671

## What Have We Learned So Far?

- A Theoretical Perspective
- Miklos Gyulassy
- Columbia University
- January 16, 2004
- Quark Matter 2004, Oakland CA

## NSAC Long Range Plan 1983

- RHIC

- QGP

## R.Stock QM04:

- “He is tethered to a tree and constrained by a fence, but the chain is not secure and the fence is low enough to leap over.
- The unicorn could escape if he wished. Clearly, however, his confinement is a happy one, to which the ripe, seed-laden pomegranates in the tree testify.”

- “Unicorn Captured”

- http://www.medieval-tapestry-wallhangings.com/unincap1.html

## Outline of My Talk:

- On the one hand, most scientists seem to think that we’re getting closer to identifying a quark-gluon plasma.
- On the other hand, there seemed to be significant disagreement on what a quark-gluon plasma IS! “

- QM04 Dilemma: J.K. Davidson,  Science Writer,  S.F.Chron.

- QCD Theory definition of QGP
- Operational definition of QGP
- Evidence for QGP as of QM04
- First hints of CGC

## PQCD theory definition of a QGP

- P(T)

- T

## pQCD theory definition of a QGP

- Transport
- Properties

- Lrad

## Weak coupling QCD theory of CGC seed of QGP

## QGP =  Bulk Collective  + Parton Dynamic + Discriminator

**	****=         P****QCD****      +     pQCD       +      dA  **
**            **

** ****My Operational definition of QGP  **

**My conclusion: “overwhelming evidence” at QM04**
**that QGP Bulk Matter  is made in AuAu** **at 200 AGeV**

- 2+3 are necessary but 1 is critical for sufficiency !

## Necessary QGP Precursors at SPS 2000

- NA50

- NA49

- Necessary QGP *Precursors* at SPS 2000

- /Drell-Yan

- Hadro Chemical Equilib

- Collective Flow

- Medium Dispersion

- pQCD

## CERES/SPS

- _Below_ RHIC energies, Bulk Flow does not reach QGP hydro!

**17 AGeV**

- CERES

**17 AGeV**

- But Critical Missing Signature of the QGP at SPS

## Bulk PQCD Hydro

**Bulk P****QCD ****Hydro**

*The* QGP Fingerprint at RHIC = Bulk collective flow  PQCD(T)

## Jet Quenching

- pQCD Parton Dynamics
- Jet Tomography

- 2nd and 3rd Lines of Evidence for QGP

## Slide 13

## Single Hadron Tomography from SPS, RHIC, LHC

**Cronin dominates at SPS**
**Cronin+Quench+Shadow**
**       ****conspire to give ~ flat**
**      ****suppression out to highest pT**
**      ****at RHIC with R~N****part****/N****bin**
**Predicts sub  N****part**** quench,**
**        ****positive pT slope of R at LHC**
**        ****and R****LHC****(40)~R****RHIC****(40)**

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

## Slide 15

## Four  independent calibrations of Initial QGP density

- Bjorken Backward extrapolation
- Hydrodynamic initial condition needed for v2(pT)
-  Jet Tomography:   dNg /dy = 1000
- Gluon saturation  pT<Qs    predicted
-                 dNg /dy = 1000  at Qsat  = 1 GeV at y=0

- KHH
- TS HN

- GLV
- WW SW

- BM
- McV
- EKRT

## The END of searching for the QGP

**The ****BEGINNING**** of measuring its properties**
** ****12D Correlations**
**  ****Heavy Quarks**
**  ****Direct Photons **
**  ****Leptons**
**  ****and its relation to CGC**

- C2

- v2

##  Indirectly, yes, as seed of QGP at y=0

-   *Possible* Hints at y=3   (BRAHMS)
-   But 30 year old soft beam physics
-        Must be first subtracted !

- Has the CGC been seen at RHIC also?

##   Soft Beam Jets : dM/M  

-   Soft Beam Jets : dM/M
- Dominate Low pT at high y

- Beam Jets

- Beam + Mini Jets

- 

- 3

- See: http://nt3.phys.columbia.edu/people/gyulassy/Talks/RBRC_120503/

- D+Au HIJING

## Proton+Emulsion data

- W. Busza review 1976
- (Acta Phys. Pol. B8, 333)

**Brodsky, Gunion, Kuhn**
** ****PRL39(77)1120**
**Color Neutralization Model**
** ****Feynman gas dy=dx/x= dM/M  **

- The low pT _*Triangle*_
- Boundary Condition
- Condition on RpA(y,pT<1)

## Preliminary: Hot-off-the-QM04-coffee-table

- Preliminary: *Hot*-off-the-QM04-coffee-table

- Addendum to Di Nezza, Steinberg talks

## Slide 22

## Appendix

## A Low pT<0.5 Triangle boundary controls

- A Low pT<0.5 *Triangle** *boundary controls
-                                     forward  rapidity      RdA D/Au

## Experimental To Do List

- -5 < Y < 5 dAu to kinematic pT bounds CGC search
- C2(phi1,phi2, pt1,pt2, eta1,eta2, fl1,fl2, Mult, A,B, Ecm)
-  Heavy Quark tomography  c and b,   Hidden quarkonia
-  Charm and Beauty Flow
-  Direct Photons thermometry
-   Tagged  direct photon -quark jets!
-  Excitation functions Ecm~50-100, A=1 - 200
-  Pentaquark factory

## Theory To Do  List

-  HBT source puzzle
-  ET/N   Ecm invariance, Npart invariance
-  vn(pT, y, m) collective flow
-  Transport properties of QGP
-  Baryon transport dynamics
-  Transient CGC -> QGP dynamics
-  QGP at finite muB

## QGP =PQCD + pQCD + dA  = v2 + (R+I) AA + (R+I)dA

- 2

- 3

- 1

- Bulk
- PQCD

- Parton
- pQCD

- Null Control

- Bulk PQCD Collective Elliptic Flow
- Parton pQCD Jet dynamics
- 3.  p+p Calibration and d+A Null Control

- Three Lines Converge to QGP at RHIC

**QGP =P****QCD**** + pQCD + dA  = v****2**** + (R+I) ****AA**** + (R+I)****dA**

## Observed Elliptic Flow at RHIC saturates hydro limit

- P.Kolb U. Heinz, et al,
- D.Teany, E. Shuryak  et al
- T. Hirano, Y. Nara

## Partonic Recombination + Fragmentation?

- Parameterized flow
- How to justify assumed vT~0.55c at T=Tc?
- Idealized hard sphere geom

- Flow is dynamically calculated PQCD
- Radial flow in hadron phase
-        is also important.
-       At T=Tc,       <vT>~0.25c
-       T=100 MeV, <vT>~0.55c

**R.Fries, B. Muller, ...**

**T.Hirano & Y.Nara**

**QGP**** Hydro + Jets**

- vs

## Jet Quenching

- XN Wang, MG

- Gluon Shadow

**P****0****=2GeV**

- Cronin

- Shadow

## Some Source Fits giving Rout=Rside=RK

- tf

## Drell-Yan andProduction at CERN/SPS

- Drell-Yan and********Production at CERN/SPS

**C. Lourenco  NA50  QM01**

**Suppressed even in p+A !!**

## Results from the SPS

- data well described by pQCD + (intrinsic + initial) kT (A,Q) broadenning
- data equally well described by hydrodynamic fit

**A. Dress QM01**

## Statistical Models Work Well at SPS and RHIC

- _Statistical Thermal Models_
*F. Becattini; P. Braun-Munzinger, J. Stachel, D. Magestro, J.Rafelski,  J.Sollfrank et al.        *_***K.Redlich***_

*** Works great, but there is not word of QCD in  such analysis. Done entirely in color neutral Hadronic basis! **
**     ****An equilibrated (Hagadorn) resonance gas was made**
**                                 ****But shows no sign of a QGP !!   **

## NA50 PbPb->J/Psi Suppression  

**NA50 PbPb->J/Psi Suppression  **

**Effect does not turn off**
**When medium is absent!**

**Predicted Non-linear **_***Initial State***_** radiative energy loss in Cold A **
**must be still tested via **_***Central***_** pA at both SPS and RHIC**

**Partonic**
**Diagnostics**

## A Low pT<0.5 Triangle boundary controls

- A Low pT<0.5 *Triangle** *boundary controls
-                                     forward  rapidity      RdA D/Au