A Dyson-Schwinger model beyond isospin limit prepared for investigating U_A(1)-breaking temperature dependence

TL;DR

This paper refits a Dyson-Schwinger model to incorporate isospin symmetry breaking, aiming to study U_A(1) symmetry restoration at finite temperature in low-energy QCD.

Contribution

It introduces isospin symmetry breaking into a Dyson-Schwinger model and refits its parameters for future finite-temperature U_A(1) symmetry investigations.

Findings

Refitted quark-mass parameters at T=0 with isospin breaking.

Enhanced model readiness for studying U_A(1) symmetry at T > 0.

Demonstrated sensitivity of topological susceptibility to quark-flavor dependence.

Abstract

Motivated by our earlier findings of sensitive quark-flavor dependence of QCD topological susceptibility on products of current quark masses and corresponding condensates, we allow the breaking of isospin symmetry. For the purpose of future investigations of U_A(1) symmetry breaking and restoration at T > 0, we perform (at T = 0) refitting of the quark-mass parameters of a phenomenologically successful effective model of low-energy QCD. It belongs to the class of separable-interaction models within the Dyson-Schwinger approach to the quark-antiquark substructure of mesons.