Infinite temperature limit of meson spectral functions calculated on the lattice

TL;DR

This paper investigates how lattice cut-off effects influence meson spectral functions at finite temperature, providing analytic results in the infinite temperature limit and demonstrating suppression of artifacts with improved fermion actions.

Contribution

It offers analytic calculations of lattice meson spectral functions at infinite temperature and compares Wilson and improved fermion actions to understand cut-off effects.

Findings

Wilson doublers significantly affect high-momentum spectral functions

Improved fermion actions reduce cut-off artifacts

Analytic results are obtained for the infinite temperature limit

Abstract

We analyze the cut-off dependence of mesonic spectral functions calculated at finite temperature on Euclidean lattices with finite temporal extent. In the infinite temperature limit we present analytic results for lattice spectral functions calculated with standard Wilson fermions as well as a truncated perfect action. We explicitly determine the influence of `Wilson doublers' on the high momentum structure of the mesonic spectral functions and show that this cut-off effect is strongly suppressed when using an improved fermion action.