Transport coefficients of gluonic fluid

Abstract

The shear ($η$) and bulk ($ζ$) 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 $η$ and $ζ$ have been evaluated for gluonic fluid with the formula derived recently. The sensitivity of the quantity, $η/s$ on the running coupling constant is also discussed. At $α_s=0.3$ we get $η/s=0.24$ which is close to the value obtained from the analysis of the elliptic flow at RHIC experiments.