Topological Susceptibility in Three-Flavor Quark Meson Model at Finite Temperature

TL;DR

This paper investigates the behavior of topological susceptibility and $U_A(1)$ symmetry in the $SU(3)$ quark meson model at finite temperature using the functional renormalization group, revealing persistent symmetry breaking.

Contribution

It introduces a fluctuation-induced component to topological susceptibility and analyzes its impact on $U_A(1)$ symmetry at high temperatures.

Findings

Topological susceptibility includes a dominant fluctuation-induced part at high temperature.

$U_A(1)$ symmetry remains significantly broken during chiral symmetry restoration.

The model provides insights into the interplay between topological effects and chiral symmetry in QCD.

Abstract

We study $U_A(1)$ symmetry and its relation to chiral symmetry at finite temperature through the application of functional renormalization group to the $SU(3)$ quark meson model. Very different from the mass gap and mixing angel between $\eta$ and $\eta'$ mesons which are defined at mean field level and behavior like the chiral condensates, the topological susceptibility includes a fluctuations induced part which becomes dominant at high temperature. As a result, the $U_A(1)$ symmetry is still considerably broken in the chiral symmetry restoration phase.