Gribov copies in the quark propagator

TL;DR

This study investigates how Gribov copies affect the quark propagator in lattice 2-color QCD, revealing volume-dependent effects and weak correlations with gauge fixing functional, contributing to understanding gauge fixing ambiguities in lattice QCD.

Contribution

It provides a detailed analysis of Gribov copy effects on the quark propagator, highlighting their volume dependence and relative magnitude compared to gluon propagator effects.

Findings

Gribov noise is comparable to gauge noise in small volumes.

Gribov noise diminishes with increasing volume.

Weak correlation between quark mass function and gauge fixing functional.

Abstract

We study the impact of Gribov copies on the quark propagator in lattice 2-colour QCD. We find that the Gribov noise is comparable to the gauge noise for smaller volumes but becomes less significant for larger spatial volumes. The Gribov noise in the quark propagator is found to be comparable to, but smaller than in the gluon propagator on the same ensembles. No correlation is found between the values of the wave function Z(p) and the value of the gauge fixing functional, nor between the two form factors. A very mild negative correlation was found between the value of the quark mass function M(p) and the gauge fixing functional.