Hard-thermal-loop Resummation of the Free Energy of a Hot Gluon Plasma

TL;DR

This paper computes the free energy of a hot gluon plasma using hard-thermal-loop perturbation theory, incorporating resummation of screening effects, quasiparticles, and damping, and compares results with lattice QCD data.

Contribution

It provides a leading-order calculation of gluon plasma free energy with all-order resummation of key thermal effects, improving agreement with lattice results.

Findings

Resummed free energy matches lattice data for T > 2 T_c

Ultraviolet divergences are canceled by temperature-independent counterterms

Next-to-leading order corrections may account for remaining discrepancies

Abstract

We calculate the free energy of a hot gluon plasma to leading order in hard-thermal-loop perturbation theory. Effects associated with screening, gluon quasiparticles, and Landau damping are resummed to all orders. The ultraviolet divergences generated by the hard-thermal-loop propagator corrections can be cancelled by a temperature-independent counterterm. The deviation of the hard-thermal-loop free energy from lattice QCD results for T > 2 T_c has the correct sign and roughly the correct magnitude to be accounted for by next-to-leading order corrections.