Hadron masses from fixed topology simulations: parity partners and SU(2) Yang-Mills results

TL;DR

This paper investigates how fixed topology in lattice QCD simulations affects hadron mass calculations, especially regarding parity mixing, and provides numerical results for SU(2) Yang-Mills theory to understand finite size effects.

Contribution

It extends existing theoretical relations to better understand correlation functions at fixed topology and presents numerical SU(2) Yang-Mills results addressing parity mixing effects.

Findings

Finite size effects cause deviations in observables at fixed topology.

Disentangling positive and negative parity states is possible with the extended relations.

Numerical results illustrate the impact of fixed topology on SU(2) Yang-Mills hadron masses.

Abstract

Lattice QCD simulations tend to get stuck in a single topological sector at fine lattice spacing, or when using chirally symmetric quarks. In such cases computed observables differ from their full QCD counterparts by finite size effects, which need to be understood on a quantitative level. We discuss extensions of existing relations from the literature between correlation functions at fixed topology and hadron masses at unfixed topology. Particular focus is put on disentangling positive and negative parity states, which mix, when the topological charge is fixed. We also present numerical results for SU(2) Yang-Mills Theory.