1. Radiative transport: comparisons between BAMPS and viscous hydro Zhe Xu with I.Bouras, A.El, O.Fochler, F.Lauciello, E.Molnar, H.Niemi, C.Greiner, D.H..Rischke CATHIE-TECHQM, BNL, Dec 14, 2009

2. Zhe Xu viscous effect described by viscous hydro, talk by H.Song Mach cone shock waves ? Comparisons between parton cascade and viscous hydro  a common understanding of phenomena Motivation

3. Zhe Xu Outline Transport model BAMPS Comparisons between BAMPS and viscous hydro 1. longitudinal Bjorken expansion, talk by A.El 2. shock waves in Riemann problem, talk by H.Niemi 3. Mach cone formation Conclusion

4. Zhe Xu BAMPS: B oltzmann A pproach of M ulti P arton S catterings A transport algorithm solving the Boltzmann-Equations for on-shell partons with pQCD interactions new development ggg gg (Z)MPC, VNI/BMS, AMPT, PACIAE Inelastic scatterings are effective in thermalization ! Transport Model

5. Zhe Xu Stochastic algorithm 3x3x collision probability -- stochastic Space is divided into small cells ! ZX and C. Greiner, PRC 71, 064901 (2005) x y

6. Zhe Xu J.F.Gunion, G.F.Bertsch, PRD 25, 746(1982) screened pQCD based partonic interactions treatment for incoherent interactions: the formation time  g : mean free path LPM suppression :

7. Zhe Xu 1. longitudinal expansion with boost invariance initial condition: local thermal equilibrium interactions: pQCD based 2  2 and 2  3 of gluons with constant  s

8. Zhe Xu extraction of the shear viscosity (Grad´s method) A. El, A. Muronga, ZX and C. Greiner, PRC 79, 044914 (2009) 1. longitudinal expansion with boost invariance

9. Zhe Xu 1. longitudinal expansion with boost invariance numbers are used in hydro calculations

10. Zhe Xu Israel-Stewart hydrodynamics 1. longitudinal expansion with boost invariance particle number conservation P. Huovinen and D. Molnar, PRC 79, 014906 (2009)

11. Zhe Xu by A. El comparisons of momentum anisotropy talk by Andrej El

12. Zhe Xu 2. Shock waves in 1-dim. Riemann problem P0 > P4 initial condition: thermal equilibrium with pressure discontinuity interactions: 2  2 with isotropic distribution of the collision angle

13. Zhe Xu by I. Bouras 2. Shock waves in 1-dim. Riemann problem

14. Zhe Xu Viscous hydro fails to describe the viscous effect in the shock front. talk by H. Niemi 2. Shock waves in 1-dim. Riemann problem Bouras et al. PRL 103, 032301 (2009) comparisons with viscous hydro calculations

15. Zhe Xu medium jet 3. Mach Cone Formation interactions: 2  2 with isotropic distribution of the collision angle

16. Zhe Xu local energy density by I. Bouras, F. Lauciello et al. 3. Mach Cone Formation

17. Zhe Xu by I. Bouras, F. Lauciello et al. 3. Mach Cone Formation local energy density

18. Zhe Xu by I. Bouras, F. Lauciello et al. 3. Mach Cone Formation local energy density

19. Zhe Xu by I. Bouras, F. Lauciello et al. 3. Mach Cone Formation local energy density

20. Zhe Xu by I. Bouras, F. Lauciello et al. 3. Mach Cone Formation local energy density

21. Zhe Xu 3. Mach Cone Formation

22. Zhe Xu medium jet 3. Mach Cone Formation

23. Zhe Xu 3. Mach Cone Formation

24. Zhe Xu 3. Mach Cone Formation viscous effect: enlarge the mach angle Comparisons with viscous hydro calculations will follow.

25. Zhe Xu longitudinal expansion with boost invariance: chemical equilibration important, 2  3 needed shock waves in Riemann problem: BAMPS is a standard to check viscous hydro caculations. Mach cone formation and flow v2, v4,...: comparisons in progress Conclusions

26. Zhe Xu Elliptic Flow and Shear Viscosity at RHIC 2-3 Parton cascade BAMPS ZX, Greiner, Stöcker, PRL 101, 2008 viscous hydro. Romatschke, PRL 99, 2007  /s > 0.08  /s at the collision center

27. Zhe Xu 3. Mach Cone Formation variation of  /s

28. Zhe Xu 3. Mach Cone Formation

29. Zhe Xu 3. Mach Cone Formation

30. Zhe Xu longitudinal flow velocity 3. Mach Cone Formation

31. Zhe Xu transverse flow velocity 3. Mach Cone Formation

32. Zhe Xu viscous effect