New Ways to Determine Low-Energy Constants with Wilson Fermions

TL;DR

This paper introduces a spectral method to determine low-energy constants in Wilson fermions, demonstrating improved accuracy and reduced higher-order constants in lattice gauge theory simulations.

Contribution

It presents a novel spectral approach for extracting low-energy constants in Wilson fermions, validated through simulations with improved Wilson fermions.

Findings

Successful individual determination of physical and Wilson low-energy constants.

Observed suppression of leading and higher-order Wilson low-energy constants.

Enhanced precision in lattice gauge theory parameter extraction.

Abstract

We show how the leading physical and Wilson low-energy constants associated with Wilson fermions in lattice gauge theory can be determined individually by using spectral information of the Wilson Dirac operator with fixed index at finite volume. The methods are demonstrated in simulations with leading-order improved Wilson fermions. In addition to the expected suppression of the leading term in Wilson chiral perturbation theory we observe a substantial reduction also of the higher-order Wilson low-energy constants.