Filtered topological structure of the QCD vacuum: Effects of dynamical quarks

TL;DR

This paper compares filtering techniques for topological structures in SU(3) lattice QCD configurations, revealing effects of dynamical quarks and artifacts of certain methods, with implications for understanding the QCD vacuum.

Contribution

It systematically analyzes and compares filtering methods, highlighting the impact of dynamical quarks on topological structures and identifying artifacts in strong smearing regimes.

Findings

Strong correlation between APE and Stout smearing results

Artifacts identified in Laplace filtering at strong smearing

Fragmented topological charge density with dynamical quarks

Abstract

We systematically compare filtering methods used to extract topological structures on SU(3) lattice configurations. We show that there is a strong correlation of the topological charge densities obtained by APE and Stout smearing. To get rid of artifacts of these methods, we analyse structures that are also seen by Laplace filtering and indeed identify artifacts for strong smearing. The topological charge density in this combined analysis is more fragmented in the presence of dynamical quarks. A power law exponent that characterises the distribution of filtered topological clusters turns out to be not far off the values of an instanton gas model.