1. Application of AdS/CFT in high energy nuclear physics Hefei, Nov 5th, 2009 黄 梅黄 梅 中国科学院高能物理研究所 中国科学院大科学装置 理论物理中心

2. 2 Content I.AdS/CFT & sQGP Shear viscosity over entropy density Equation of state Bulk viscosity over entropy density II. AdS/CFT & hadron physics Hard wall AdS 5 model Soft-wall AdS 5 model Dp-Dq model

3. 3 The birth of string theory in 1960’s was to understand strong interaction. It’s the time for string theory coming back to finish its original task !?

4. 4 AdS/CFT Maldacena (1997)

5. 5 QCDQCD ? String theory, quantum gravity Non-Abelian gauge theory AdS/CFT conjecture If it’s true for any gauge theory Then what ’ s the dual string theory of QCD?

6. 6 Metric structure of holographic QCD (5D) QCD Dp-Dq system in type-II superstring theory (10D) First step, is it possible to find a 5D holographic model of QCD?

7. 7 I. AdS/CFT & sQGP Shear viscosity over entropy density Equation of state Bulk viscosity over entropy density what I didn’t cover in this talk: energy loss, (H.Liu et.al., Y.Gao et.al. and many others) heavy quark dissociation (Hou, Ren and many others) ……

8. 8 Discovery of sQGP at RHIC Low shear viscosity Shear viscosity over entropy density

9. 9 Increase shear viscosity reduces elliptic flow! P. Romatschke, U. Romatschke, nucl-th/0706.1522 Before 2003, people believed that de-confined QCD matter would be weakly coupled gas, pQCD gives: See Qun Wang’s talk

10. 10 Handling strongly coupled system by using AdS/CFT Minimum bound?

11. 11 Universality of  /s=1/4  ? Violation of the minimum bound in higher derivative gravity / dilaton coupling M. Brigante, H. Liu, R.C. Myers, S. Shenker, S. Yaido 0712.0805, 0802.3318 R.G. Cai, Z.Y. Nie, N. Ohta, Y.W. Sun, 0901.1421 S.Pu, Q. Wang,0810.5271

12. 12 sQGP: Most “perfect fluid” known Lattice: Nakamura-Sakai(2004) Meyer (2007) Water Policastro, Son, and Starinets; Kovton, Son and Starinets; Buchel, J. Liu; Maeda, Natsuume, Okamura N =4 SYM : RHIC: Teaney (2003) Romatschke-Romatschke (2007)

13. 13 However, QCD is not a conformal theory Trace anomaly Nonzero bulk viscosity AdS/CFT QCD

14. 14 LQCD results: trace anomaly shows a sharp peak near phase transition BNL-Columbia-RBRC-Bielefeld, arXiv:0710.0354 Bielefeld, hep-lat/9602007 Non-conformality: EOS and bulk viscosity over entropy density

15. 15 BNL-Columbia-RBRC-Bielefeld arXiv:0710.0354 LQCD results: soft EOS & small sound velocity near phase transition

16. 16 Dmitri Kharzeev, Kirill Tuchin arXiv:0705.4280 [hep-ph], F.Karsch, Dmitri Kharzeev, Kirill Tuchin arXiv:0711.0914 [hep-ph], Harvey Meyer arXiv:0710.3717 [hep-ph], Nonzero bulk viscosity of QCD matter near phase transition Pure gluodynamics 2-flavor case

17. 17 Gubser et al, 0804.1950 5D Gravity couples to a dilaton, nonconformal

18. 18 J.W Chen, MH, Y.H. Li, E. Nakano, D.L.Yang arXiv: 0709.3434 Baochun Li, Mei Huang, arXiv: 0807.0292 Scalar theory: Minimum at Tc for shear viscosity over entropy density Maximum at Tc for bulk viscosity over entropy density Dual theory: Minimum at Tc for shear viscosity over entropy density (no result) Maximum at Tc for bulk viscosity over entropy density (yes)

19. 19 J. Noronha, 0910.1261

20. 20 II.AdS/CFT & Hadron Physics hard-wall AdS5 model soft-wall AdS5 model Dp-Dq model

21. Can AdS 5 metric describe hadron spectra? hard-wall AdS 5 model

22. Lowest excitations: 10-20% agreement

23. However, no Regge behavior in the hard-wall AdS 5 model !

24. How to improve AdS 5 metric? Introduce a dilaton field to restore Regge behavior soft-wall AdS 5 model or KKSS model

25. 25 No Regge behavior for axial meson in soft-wall AdS 5 model S. He, M. Huang, Q. S. Yan, Y. Yang, 0710.0988

26. 26 Dp-Dq model S. He, M. Huang, Q. S. Yan, Y. Yang, 0710.0988

27. 27

28. 28 19 scalars below 2GeV Below 1 GeV, tetraquark nonet (inverse mass odering) Above 1GeV, quark antiquark nonet + one glueball

29. 29 Operator and 5D mass

30. 30 Spectra in Dp-Dq model: D4 background is more favored C. Wang, S. He, M. Huang, Q. S. Yan, Y. Yang, 0902.0864

31. 1.It seems possible to describe QCD properties using holographic method, 2.Still need a lot of efforts to find the right holographic QCD model. In summary Welcome to KITPC program “AdS/CFT and Novel Approaches to Hadron and Heavy Ion Physics” From 2010 -10-11 to 2010-12-03, KITPC

33. 33 Relativistic Heavy Ion Collision Discovery of “Perfect fluid” at RHIC Hydrodynamics ???

34. 34 A little bit Hydrodynamics

35. 35 x Non-central Collisions beam y x pypy pxpx Elliptic Flow v2