Chiral Phase Transition beyond Mean Field Approximation

TL;DR

This paper explores how including quark-antiquark pair fluctuations beyond mean field affects the chiral phase transition, revealing a lowered critical temperature and quark mass generation above it.

Contribution

It introduces a self-consistent T-matrix approach to incorporate pair fluctuations in the chiral phase transition analysis, extending beyond traditional mean field methods.

Findings

Pair fluctuations lower the critical temperature significantly.

Quarks acquire mass even above the transition temperature.

The $G_0 G$ scheme effectively models fluctuation effects.

Abstract

Based on the analogy between the Nambu--Jona-Lasinio model of chiral symmetry breaking and the BCS theory of superconductivity, we investigate the effect of $\bar q q$ pair fluctuations on the chiral phase transition. We include uncondensed $\bar q q$ pairs at finite temperature and chemical potential in a self-consistent T-matrix formalism, the so-called $G_0 G$ scheme. The pair fluctuations reduce significantly the critical temperature and make quarks massive above the critical temperature.