Cutoff effects of Wilson fermions on the QCD equation of state to O(g^2)

TL;DR

This paper calculates the O(g^2) cutoff effects of Wilson fermions on the QCD equation of state, comparing different formulations and continuum approaches to understand discretization impacts in lattice QCD simulations.

Contribution

It provides a detailed perturbative analysis of cutoff effects for various Wilson fermion formulations, including finite mass effects, and compares them with staggered fermions.

Findings

Wilson fermions have cutoff effects comparable to staggered fermions for N_t ≥ 8.

Asymptotic scaling requires N_τ > 10 for Wilson fermions.

Finite mass effects are included in the perturbative calculations.

Abstract

We compute the O(g^2) contribution to the thermodynamic pressure for Wilson fermions in the standard, the twisted mass, and clover improved formulation in lattice perturbation theory, including finite mass effects. We compare the continuum approaches of these discretizations for the massive ideal and interacting gas. In all cases, for N_t \geq 8 cutoff effects of Wilson type fermions are comparable to those of staggered fermions, but asymptotic scaling requires $N_\tau>10$.