1. 7 th Workshop on QCD and RHIC Physics Xin-Nian Wang Lawrence Berkeley National Laboratory Hard Probes at RHIC: a Theoretical Overview Hefei, July 9-13, 2008

2. 7 th National Workshop on QCD and Relativistic Heavy-ion Collision Physics Workshop on QCD and RHIC Physics, Wuhan, 2002 First meeting in 2001, CCAST, Beijing

3. Learning & exchange of ideas

4. Fun & friendship

5. New Discoveries

6. What has happened since then Chinese STAR Collaboration: MPRC project for TOF Chinese ALICE Collaboration Major NSFC Project on RHIC Theory and Phenomenology

7. Empirical Evidence of sQGP at RHIC Hydro-dynamics calc. Pedestal&flow subtracted

8. A “Perfect Liquid” or sQGP? Liquid, fluid and (strongly coupled) plasma Characteristic of liquid or gas: pair correlation Thoma’ 2006 Yu, Xu, Liu & Liu, 2008

9. How small is the  /s?

10. Room for some range of  /s Huovinen’08 C Geiner & Z. Xu’08

11. q-hat and Shear Viscosity  Majumder, Muller and XNW’07 Shear viscosity Jet quenching 

12. Jet transport in medium Ap 0 y q q Jet Transport Operator Classical correspondence: … Liang, XNW & Zhou’08

13. Maximal Two-gluon Correlation

14. Medium Broadening Liang, XNW & Zhou’08 Majumder & Muller’07 Kovner & Wiedemann’01 Jet transport parameter Solution of diffusion eq.

15. Jet transport parameter & Saturation Gluon saturation Kochegov & Mueller’98 McLerran & Venugapolan’95 Multi-gluon correlation: Casalderrey-Salana, & XNW’07 DGLAP

16. Measuring qhat Direct measurement: or modified fragmentation function Measuring parton energy loss GW:Gyulassy & XNW’04 BDMPS’96 LCPI:Zakharov’96 GLV: Gyulassy, Levai & Vitev’01 ASW: Wiedemann’00 HT: Guo & XNW’00 AMY: Arnold, Moore & Yaffe’03 q Ap xp Ap q x 1 p+k T

17. Hadron suppression & medium properties Bass et al’08 Cold nuclear matter in DIS Wang & XNW’01 Majumder, Wang & XNW’07 OWWZ: Owen, Wang, XNW & Zhang’08

18. Gamma-jet: toward a true tomography Isolated photons as tags: HSW’96, OWWZ’08 Huang, Sarcevic & XNW’96 Volume emission for small z T Surface emission for large z T >1

19. Jet Quenching phenomenology -fit to single hadron Raa in Au+Au at all centralities at RHIC energy Phenix’08, see Nagle’s talk OWWZ’08 TECHQM

20. Theoretical improvements Elastic vs radiative: for finite E & L Qin, et al ‘’08 Recoil in radiative process: Quark-annihilation Flavor changing process q Ap q NLO corrections to LO collinear factorized contribution Mass correction for heavy quarks

21. Heavy Quarks  E el for heavy quark is larger than light quarks Langevin Eq. for v<<1 Moore & Teaney’05 pQCD Strong coupling SYM Casalderrey-Solana & Teaney’06 Gubser’06, Herzog et al’06 Rcb Ratio Horowitz & Gyulassy’08 Wicks et al’06,Djordjevic et al’06

22. Armesto, et al’08 Inclusion of multiple gluon emission Modified DGLAP Evolution Eq. Guo & XNW’00 q Ap q Renk’08

23. Effects of hydrodynamics 1D vs. 2+1D Faster decrease in  but increased duration Gyulassy, et al’02 Viscous hydro, 3-D haydro: effects are expected to be small Some decrease in anisotropy of  E in 1+2D without effect of flow Gyulassy, et al’02 Effect of flow Baier, Mueller &Schiff’06 Liu, Rajagopal & Wiedemann’06

24. Azimuthal anisotropy OWWZ’ 2008 Bass et al’08 20-30% 1+1D Bjorken 1+2D hydro

25. Medium response to jets Sonic mach cones induced by propagating jets Stocker’05, Casaderrey-Solana, Shuryak & Teaney’05 Mach cone angle: Sound attenuation  with of the cone structure: Neufeld, Muller & Ruppert’08 pQCD  /s=1/4  Chesler & Yaffe;07 Fries et al’07 SYM

26. Cone & ridge in parton cascade Double peak structure was seen in AMPT simulation Ma, et al ‘06 p T =0~1GeV/c Soft hadrons associated with a jet Minimum distance required Ridge along tangential jets punch-through jets tangential jets Longitudinal flow (Armesto et al’05) Longitudinal field (Majumder et al’07) Recombination (Hwa’05, Wong’ 07)

27. Summary sQGP still needs to be quantified Jet transverse momentum broadening provides a lot of information about the medium: gluon density, gluon correlations, etc, all characterized by jet transport parameter qhat Jet quenching provided an indirect measurement of qhat Jet quenching phenomenology has advanced to more quantitative analysis More exclusive studies such as gamma-jet and medium excitation are necessary