The chirally improved quark propagator and restoration of chiral symmetry

TL;DR

This paper computes the chirally improved quark propagator in lattice QCD, analyzing its properties and the effects of low-mode removal on chiral symmetry restoration, with implications for understanding nonperturbative QCD dynamics.

Contribution

It provides a detailed lattice calculation of the CI quark propagator with improved techniques and explores chiral symmetry restoration via low-mode removal effects.

Findings

Mass function's infrared mass dissolves with low-mode removal

Strong suppression of wave-function renormalization at low momenta

Tree-level improvements reduce lattice artifacts

Abstract

The chirally improved (CI) quark propagator in Landau gauge is calculated in two flavor lattice Quantum Chromodynamics. Its wave-function renormalization function $Z(p^2)$ and mass function $M(p^2)$ are studied. To minimize lattice artifacts, tree-level improvement of the propagator and tree-level correction of the lattice dressing functions is applied. Subsequently the CI quark propagator under Dirac operator low-mode removal is investigated. The dynamically generated mass in the infrared domain of the mass function is found to dissolve continuously as a function of the reduction level and strong suppression of $Z(p^2)$ for small momenta is observed.