Theory Seminar (2010)

KEK 素粒子原子核研究所・理論セミナー

　 　
　 　
　 　
　 　

　TITLE:

Critical dynamics near QCD critical point based on dynamic renormalization group theory 　
(In Japanese)

　SPEAKER:

 南　佑樹　氏　(京都大学)
 Yuki Minami, Kyoto Univ.

　DATE:

 Dec. 20 (Mon.) 14:00-16:00

　PLACE:

 Meeting Room 2, Kenkyu-Honkan
 

 Abstract

Although some authors suggested a divergent behavior of bulk viscosityas a critical phenomenon around QCD critical point(CP) [1],their argument seems not on a sound basis but of much controversies[2].Thus, it is still uncertain whetherthe transport coefficients would show a divergent behavior near the QCD CP.

 

In this talk, we analyze the critical behaviors of the transport coefficientsusing the dynamic renormalization group(RG) theory.For this purpose, we first construct the nonlinear Langevin equation near the QCD CP on using
the relativistic fluid dynamics because the critical modes around the QCD CP are the conserved densities[3]. Applying the dynamic RG to the equation, we extract dynamic critical exponents:We find that the bulk viscosity and the thermal conductivity show a strong divergence,and thereby they can be more important than the shear viscosity near the QCD CP.We shall also show that the thermal and viscous diffusion modes exhibit critical slowing down
while the sound mode exhibits critical speeding up.  

 

References:

 

[1]F.Karsch,D.Kharzeev and K.Tuchin,Phys. Lett. B 663, (2008), 217.

 

[2] G.D.Moore and O.Saremi, JHEP 0809 (2008) 015;

    P.Romatschke and D.T.Son, arXiv:0903.3946 [hep-ph];

    C.Sasaki and K.Redlich, Nucl.Phys. A 832 (2010),62.

 

[3] H.Fujii and M.Ohtani, Phys. Rev. D 70 (2004), 014016;

    D.T.Son and M.A.Stephanov, Phys. Rev. D 70 (2004), 056001.