Light Quarks Beyond Chiral Limit

TL;DR

This paper introduces an improved QCD effective action that incorporates current quark masses, enhancing the modeling of strange quarks and validated through calculations of quark condensates and meson properties.

Contribution

The paper presents a novel Improved Effective Action based on Lee-Bardeen results, improving the treatment of current quark masses in QCD effective models.

Findings

Accurately accounts for current quark masses, especially for strange quarks.

Successfully reproduces quark condensate and pseudoscalar meson masses.

Validates the approach with axial-anomaly low-energy theorems.

Abstract

In this talk we discuss an improvement of the Diakonov-Petrov QCD Effective Action. We propose the Improved Effective Action, which is derived on the basis of the Lee-Bardeen results for the quark determinant in the instanton field. The Improved Effective Action provides proper account of the current quark masses, which is particularly important for strange quarks. This Action is successfully tested by the calculations of the quark condensate, the masses of the pseudoscalar meson octet and by axial-anomaly low-energy theorems.