Taste violations in the scalar correlator in mixed action simulations

TL;DR

This paper investigates taste violations in the scalar correlator within mixed action lattice QCD simulations, confirming that unitarity violations align with predictions from mixed-action chiral perturbation theory.

Contribution

It provides empirical verification that taste-breaking effects dominate unitarity violations in mixed action lattice QCD, matching theoretical predictions.

Findings

Data agrees with chiral perturbation theory predictions

Taste-breaking effects explain unitarity violations

Validates mixed-action chiral perturbation theory model

Abstract

We study the behavior of the isovector scalar correlator, which is particularly sensitive to lattice artifacts, using domain-wall valence quarks on a staggered sea (generated by the MILC collaboration). We analyze this according to the prediction from chiral perturbation theory determined by Prelovsek, which indicates that the leading unitarity violations come from taste breaking effects. We show that our data behaves in the way predicted by Prelovsek, thus verifying that the largest contribution to the violations of unitarity which arise at finite lattice spacing can be described by the mixed-action chiral perturbation theory.