The dependence of overlap topological charge density on Wilson mass parameter

TL;DR

This paper investigates how the topological charge density derived from the overlap operator depends on the Wilson mass parameter, comparing fermionic and gluonic definitions to optimize measurement accuracy.

Contribution

It introduces a matching procedure to align fermionic and gluonic topological charge densities, enabling estimation of the proper Wilson flow time across different lattice spacings.

Findings

Non-trivial topological objects are removed with increasing Wilson mass.

A best match exists between fermionic and gluonic topological charge densities.

Proper Wilson flow time decreases as lattice spacing decreases.

Abstract

In this paper, we analyze the dependence of the topological charge density from the overlap operator on the Wilson mass parameter in the overlap kernel by the symmetric multi-probing source (SMP) method. We observe that the non-trivial topological objects are removed as the Wilson mass is increased. A comparison of topological charge density calculated by the SMP method using fermionic definition with that of gluonic definition by the Wilson flow method is shown. A matching procedure for these two methods is used. We find that there is a best match for topological charge density between gluonic definition with varied Wilson flow time and fermionic definition with different Wilson mass. By using the matching procedure, the proper flow time of Wilson flow in the calculation of topological charge density can be estimated. As the lattice spacing $a$ decreases, the proper flow time also decreases, as expected.