On the continuum limit of Landau gauge gluon and ghost propagators in SU(2) lattice gauge gluodynamics

TL;DR

This study investigates the continuum limit of Landau gauge gluon and ghost propagators in SU(2) lattice gauge theory, analyzing lattice artifacts and the impact on physical observables across large lattice sizes.

Contribution

It provides a systematic analysis of lattice artifacts in gluon and ghost propagators using large lattices and compares their behavior to continuum expectations.

Findings

Strong lattice artifacts observed for gluon and ghost propagators at low momenta.

Gluon propagator's dependence on lattice spacing complicates continuum extrapolation.

Running coupling appears less affected by lattice artifacts.

Abstract

We continue the systematic computation of Landau gauge gluon and ghost propagators of SU(2) gluodynamics using a sequence of increasing lattice sizes L^4 up to L=112 with corresponding \beta-values chosen to keep the linear physical size a(\beta)L ~ 9.6 fm fixed. To extremize the Landau gauge functional we employ simulated annealing combined with subsequent overrelaxation. Renormalizing the propagators at momentum \mu= 2.2 GeV we observe quite strong lattice artifacts for the gluon propagator as well as for the ghost dressing function within the momentum region q < 1.0 GeV. The dependence on the lattice spacing for the gluon propagator at lowest accessible physical momentum values does not yet allow a simple extrapolation to the continuum limit. On the contrary, the running coupling derived from the bare dressing functions seems less affected by lattice artifacts.