Strong-coupling effects in a plasma of confining gluons

TL;DR

This paper investigates the properties of a gluon plasma derived from confining gluons using Gribov quantization, deriving viscosity coefficients and showing its strongly-coupled, nearly perfect fluid behavior at high temperatures.

Contribution

It provides analytical expressions for bulk and shear viscosities in a confining gluon plasma, highlighting properties similar to strongly-coupled theories and the quark-gluon plasma.

Findings

Viscosity coefficients derived analytically.

Bulk to shear viscosity ratio scales with conformality breaking.

Plasma exhibits properties of an almost perfect fluid.

Abstract

The plasma consisting of confining gluons resulting from the Gribov quantization of the SU(3) Yang-Mills theory is studied using non-equilibrium fluid dynamical framework. Exploiting the Bjorken symmetry and using linear response theory a general analytic expressions for the bulk and shear viscosity coefficients are derived. It is found that the considered system exhibits a number of properties similar to the strongly-coupled theories, where the conformality is explicitly broken. In particular, it is shown that, in the large temperature limit, bulk to shear viscosity ratio, scales linearly with the difference $1/3 - c_s^2$, where $c_s$ is the speed of sound. Results obtained from the analysis are in line with the interpretation of the quark-gluon plasma as an almost perfect fluid.