Eur. Phys. J. Special Topics 229, 3363–3370 (2020)
https://doi.org/10.1140/epjst/e2020-000073-5

Regular Article

A Dyson-Schwinger model beyond isospin limit

prepared for investigating U_A(1)-breaking temperature dependence

¹ Physics Department, Faculty of Science-PMF, University of Zagreb, Bijenička cesta 32, 10000 Zagreb, Croatia
² Rugjer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia

^a e-mail: klabucar@phy.hr

Received: 22 April 2020
Accepted: 27 October 2020
Published online: 21 December 2020

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.