Constituent and current quark masses at low chiral energies

TL;DR

This paper determines light constituent and dynamical quark masses using data, the Quark-Level Linear σ Model, and infrared QCD, providing accurate effective current quark masses and insights into light meson masses.

Contribution

It introduces a method to define effective nonstrange and strange current quark masses that accurately reproduce pion and kaon masses, contrasting with traditional Chiral Perturbation Theory.

Findings

Effective nonstrange and strange current quark masses match experimental meson masses.

Light scalar meson masses are derived from constituent quark masses.

Traditional current quark masses do not easily explain meson masses.

Abstract

Light constituent quark masses and the corresponding dynamical quark masses are determined by data, the Quark-Level Linear $\sigma$ Model, and infrared QCD. This allows to define effective nonstrange and strange current quark masses which reproduce the experimental pion and kaon masses very accurately, by simple additivity. Moreover, the masses of the light scalar mesons $\sigma(600)$ and $\kappa(800)$ can be obtained straightforwardly from the constituent quark masses. In contrast, the usual nonstrange and strange current quark masses employed by Chiral Perturbation Theory do not allow a simple quantitative explanation of the pion and kaon masses.