Fluctuations and the axial anomaly with three quark flavors

TL;DR

This paper investigates how the axial anomaly affects the chiral phase transition in three-flavor quark matter using a non-perturbative functional renormalization group approach, highlighting the impact of fluctuations and symmetry breaking.

Contribution

It introduces a non-perturbative FRG method to analyze the axial anomaly's role in the chiral transition with three quark flavors, comparing with mean-field results.

Findings

Fluctuations significantly influence the phase transition.

U(1)_A-symmetry breaking affects the critical endpoint.

Quark mass variations alter the phase diagram.

Abstract

The role of the axial anomaly in the chiral phase transition at finite temperature and quark chemical potential is investigated within a non-perturbative functional renormalization group approach. The flow equation for the grand potential is solved to leading-order in a derivative expansion of a three flavor quark-meson model truncation. The results are compared with a standard and an extended mean-field analysis, which facilitates the exploration of the influence of bosonic and fermionic fluctuations, respectively, on the phase transition. The influence of U(1)_A-symmetry breaking on the chiral transition, the location of a possible critical endpoint in the phase diagram and the quark mass sensitivity is studied in detail.