Remarks on the discretization of physical momenta in lattice QCD

TL;DR

This paper proposes a method using two different boundary conditions for two fermion species in lattice QCD to address the issue of discretized physical momenta, supported by numerical evidence.

Contribution

It introduces a novel boundary condition technique in lattice QCD to better handle physical momenta discretization, improving the calculation of physical observables.

Findings

Numerical results support the physical relevance of the proposed boundary condition method.

The method effectively mitigates the effects of momentum quantization in finite lattice simulations.

The approach enhances the accuracy of lattice QCD calculations for phenomenological processes.

Abstract

The calculation on the lattice of cross--sections, form--factors and decay rates associated to phenomenologically relevant physical processes is complicated by the spatial momenta quantization rule arising from the introduction of limited box sizes in numerical simulations. A method to overcome this problem, based on the adoption of two distinct boundary conditions for two fermions species on a finite lattice, is here discussed and numerical results supporting the physical significance of this procedure are shown.