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ID 23365
file
creator
Sakai, S.
NDC
Physics
abstract
We present transport coefficients (shear viscosity, η, and bulk viscosity, ζ) for the gluon system obtained by the lattice QCD. This is an indispensable calculation towards the understanding of "New State of Matter" observed in RHIC. We study the temperature regions of RHIC (1.4 ≤ T / Tc ≤ 1.8) and much higher ones up to T / Tc ~ 20. In RHIC regions, the ratio of shear viscosity to entropy density, η / s, is around ~ 0.1 - 0.4, and satisfies the KSS bound. At high temperature, η becomes two or three oder of magnitude larger.

Our calculation has two limitations: (i) the use of the quench approximation, i.e., without quark pair creation-annihilation effects on vacuum, and (ii) the use of an ansatz for the spectral function. The first point has been well studied in calculations of the spectroscopy and the phase-transition behavior. To investigate the second point, we compare our results with perturbative calculations in high T-regions, and also check the effects of the modification of the spectral function on the viscosity.
journal title
Nuclear Physics A
volume
Volume 774
issue
Issue 1-4
start page
775
end page
778
date of issued
2006-08
publisher
Elsevier B.V.
issn
0375-9474
ncid
publisher doi
language
eng
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
author
rights
Copyright (c) 2006 Elsevier B.V.
relation url
department
Information Media Center