Quark mass effects on the topological susceptibility in QCD

TL;DR

This study examines how quark masses influence topological susceptibility in lattice QCD with dynamical Wilson fermions, confirming theoretical expectations and exploring correlations with light hadronic observables.

Contribution

It provides a detailed comparison of fermionic and gluonic topological charge definitions and investigates the quark mass dependence of topological susceptibility in lattice QCD.

Findings

Agreement between fermionic and gluonic topological charge measurements

Topological susceptibility follows the expected quark mass dependence

Effects observed in the flavour singlet pseudoscalar channel

Abstract

We investigate topology in lattice simulations of QCD with two flavours of dynamical Wilson fermions. At various sea quark masses we find reasonable agreement between results for the topological charge from fermionic and gluonic definitions, the latter with cooling. We study correlations of the topological charge with light hadronic observables and find effects in the flavour singlet pseudoscalar channel. The quark mass dependence of the topological susceptibility, $\chi$, is in agreement with the leading order small m_pi expectation, chi=(f_pi m_pi)^2/4.