Transport coefficients of gluonic fluid

Abstract

The shear ($\eta$) and bulk ($\zeta$) viscous coefficients have been evaluated for a gluonic fluid. The elastic, $gg \rightarrow gg$ and the inelastic, number non-conserving, $gg\rightarrow ggg$ processes have been considered as the dominant perturbative processes in evaluating the viscous co-efficients to entropy density ($s$) ratios. Recently the processes: $gg \rightarrow ggg$ has been revisited and a correction to the widely used Gunion-Bertsch (GB) formula has been obtained. The $\eta$ and $\zeta$ have been evaluated for gluonic fluid with the formula derived recently. The sensitivity of the quantity, $\eta/s$ on the running coupling constant is also discussed. At $\alpha_s=0.3$ we get $\eta/s=0.24$ which is close to the value obtained from the analysis of the elliptic flow at RHIC experiments.