Chiral Symmetry in Two-Color QCD at Finite Temperature

TL;DR

This paper investigates the behavior of chiral symmetry in two-color QCD at finite temperature, revealing a first order phase transition under certain conditions, with implications for lattice studies.

Contribution

It provides a detailed analysis of chiral symmetry restoration in two-color QCD, highlighting the order of phase transitions depending on flavor number and instanton effects.

Findings

First order phase transition for two or more flavors at finite temperature.

Symmetry restoration remains first order with instantons for three or more flavors.

Results are relevant for lattice QCD studies of chiral symmetry.

Abstract

We study the chiral symmetry in two-color QCD with N massless flavors at finite temperature, using an effective theory. For the gauge group SU(2), the chiral symmetry is enlarged to SU(2N), which is then spontaneously broken to Sp(2N) at zero temperature. At finite temperature, and when the axial anomaly can be neglected, we find a first order phase transition occurring for two or more flavors. In the presence of instantons, the symmetry restoration unambiguously remains first order for three or more massless flavors. These results could be relevant for lattice studies of chiral symmetry at finite temperature and density.