The lattice Landau gauge gluon propagator: lattice spacing and volume dependence

TL;DR

This study investigates how finite lattice spacing and volume affect the lattice Landau gauge gluon propagator in QCD, finding that lattice spacing primarily influences infrared behavior, with finer lattices enhancing the propagator.

Contribution

It provides a detailed analysis of the effects of lattice spacing and volume on the gluon propagator, highlighting the dominant role of lattice spacing in infrared region modifications.

Findings

Finite lattice spacing significantly impacts the infrared gluon propagator.

Reducing lattice spacing enhances the infrared propagator.

Data at β=5.7 sets a lower bound for the infinite volume propagator.

Abstract

The interplay between the finite volume and finite lattice spacing is investigated using lattice QCD simulations to compute the Landau gauge gluon propagator. Comparing several ensembles with different lattice spacings and physical volumes, we conclude that the dominant effects, in the infrared region, are associated with the use of a finite lattice spacing. The simulations show that decreasing the lattice spacing, while keeping the same physical volume, leads to an enhancement of the infrared gluon propagator. In this sense, the data from $\beta=5.7$ simulations, which uses an $a \approx 0.18$ fm, provides a lower bound for the infinite volume propagator.