Perturbative subtraction of lattice artifacts in the computation of renormalization constants

TL;DR

This paper proposes a perturbative subtraction method to reduce lattice artifacts in the computation of renormalization constants, improving the precision of lattice QCD calculations.

Contribution

It introduces a one-loop perturbative subtraction technique to suppress lattice artifacts in the nonperturbative determination of renormalization factors.

Findings

Complete one-loop subtraction reduces lattice artifacts more effectively.

Comparison shows $O(a^2)$ subtraction is less comprehensive.

Improved accuracy in renormalization constants computation.

Abstract

The determination of renormalization factors is of crucial importance. They relate the observables obtained on finite, discrete lattices to their measured counterparts in the continuum in a suitable renormalization scheme. Therefore, they have to be computed as precisely as possible. A widely used approach is the nonperturbative Rome-Southampton method. It requires, however, a careful treatment of lattice artifacts. They are always present because simulations are done at lattice spacings $a$ and momenta $p$ with $ap$ not necessarily small. In this paper we try to suppress these artifacts by subtraction of one-loop contributions in lattice perturbation theory. We compare results obtained from a complete one-loop subtraction with those calculated for a subtraction of $O(a^2)$.