Polyakov loop and the color-flavor locked phase of Quantum Chromodynamics

TL;DR

This paper investigates the impact of the Polyakov loop on the phase transition in high-density QCD, finding it raises the critical temperature and does not alter the critical exponent near the transition.

Contribution

It introduces the Polyakov loop into the Nambu Jona Lasinio model for color-flavor locked phase and quantifies its effects on critical temperature and phase transition properties.

Findings

Critical temperature $T_c$ increases by 1.5-2 times with the Polyakov loop.

The Polyakov loop does not change the critical exponent of the phase transition.

Inclusion of the Polyakov loop enhances the model's realism at high density.

Abstract

We consider the Polyakov Nambu Jona Lasinio model with three massless quarks at high density and moderate temperature in the superconductive color flavor locking phase. We compute the critical temperature $T_c$ as a function of the baryonic chemical potential for the phase transition from the superconductive state to the normal phase. We find that $T_c$ is higher by a factor 1.5 -2 in comparison to the model containing no Polyakov loop. We also compute the specific heat $C_v$ near the second order phase transition and we show that the inclusion of the Polyakov loop does not change the value of the critical exponent.