The Influence of Instantons on the Quark Propagator

TL;DR

This study investigates how instantons influence the quark propagator by using lattice gauge theory techniques, demonstrating that instantons play a key role in dynamical mass generation in quantum chromodynamics.

Contribution

The paper introduces a method to produce gauge configurations dominated by instantons and analyzes their effect on the quark propagator, highlighting instantons' role in mass generation.

Findings

Instantons significantly contribute to dynamical mass generation.

Smearing effectively isolates instanton effects without destroying long-range gauge structures.

Configurations dominated by instantons reproduce most of the observed mass generation.

Abstract

We use over-improved stout-link smearing to investigate the presence and nature of instantons on the lattice. We find that smearing can remove short-range effects with little damage to the long-range structure of the gauge field, and that after around 50 sweeps this process is complete. There are more significant risks for very high levels of smearing beyond 100 sweeps. We are thus able to produce gauge configurations dominated by instanton effects. We then calculate the overlap quark propagator on these configurations, and thus the non-perturbative mass function. We find that smeared configurations reproduce the majority of dynamical mass generation, and conclude that instantons are primarily responsible for the dynamical generation of mass.