Three-flavor chiral phase transition and axial symmetry breaking with the functional renormalization group

TL;DR

This study uses the functional renormalization group to explore how mesonic fluctuations and axial symmetry breaking influence the QCD phase diagram, especially the critical endpoint, in a three-flavor quark-meson model.

Contribution

It provides new insights into the effects of axial $U(1)_A$-symmetry breaking on the chiral phase transition and critical endpoint location within a three-flavor framework.

Findings

Mesonic fluctuations significantly affect the phase transition.

Axial $U(1)_A$-symmetry breaking shifts the critical endpoint.

Quark mass variations alter the transition characteristics.

Abstract

The interplay of mesonic fluctuations with an axial $U(1)_A$-symmetry breaking and resulting effects on the location of a possibly existing critical endpoint in the QCD phase diagram are investigated in a framework of the functional renormalization group within a $N_f = 2 + 1$ flavor quark-meson model truncation. The axial $U(1)_A$-symmetry breaking is imposed by a mesonic Kobayashi-Maskawa-'t Hooft determinant. The quark mass sensitivity of the chiral phase transition with and without the $U(1)_A$-symmetry breaking is studied.