Color neutrality effects in the phase diagram of the PNJL model

TL;DR

This paper studies how imposing color neutrality in the PNJL model alters its phase diagram, leading to a reduced chiral symmetry breaking region, a shifted critical point, and coexistence of phases, due to a nonzero color chemical potential.

Contribution

It provides a detailed analysis of the impact of color neutrality constraints on the phase structure of the PNJL model, highlighting the role of the color chemical potential.

Findings

Shrinks the chiral symmetry breaking domain in the T-mu plane

Shifts the critical point to lower temperatures

Enables coexistence of chiral symmetry breaking and superconducting phases

Abstract

The phase diagram of a two-flavor Polyakov loop Nambu-Jona-Lasinio model is analyzed imposing the constraint of color charge neutrality. Main effects of this constraint are a shrinking of the chiral symmetry breaking (chiSB) domain in the T-mu plane, a shift of the critical point to lower temperatures and a coexistence of chiSB and two-flavor superconducting phases. The effects can be understood in view of the presence of a nonvanishing color chemical potential mu_8, which is necessary to compensate the color charge density rho_8 induced by the nonvanishing Polyakov-loop mean field phi_3.