Quark propagator with two flavors of O(a)-improved Wilson fermions

TL;DR

This study computes the Landau gauge quark propagator in lattice QCD with two flavors of improved Wilson fermions, analyzing effects of lattice spacing, volume, and quark mass on the propagator's properties.

Contribution

It provides a detailed lattice QCD calculation of the quark propagator with improved Wilson fermions, including analysis of lattice artifacts and finite volume effects.

Findings

Quark wave function suppression increases as quark mass decreases.

Volume effects weaken the suppression of the wave function in the infrared.

Weak volume dependence observed in the quark mass function.

Abstract

We compute the Landau gauge quark propagator from lattice QCD with two flavors of dynamical O(a)-improved Wilson fermions. The calculation is carried out with lattice spacings ranging from 0.06 fm to 0.08 fm, with quark masses corresponding to pion masses of 420, 290 and 150 MeV, and for volumes of up to (4.5fm)^4. Our ensembles allow us to evaluate lattice spacing, volume and quark mass effects. We find that the quark wave function which is suppressed in the infrared, is further suppressed as the quark mass is reduced, but the suppression is weakened as the volume is increased. The quark mass function M(p^2) shows only a weak volume dependence. Hypercubic artefacts beyond O(a) are reduced by applying both cylinder cuts and H4 extrapolations. The H4 extrapolation shifts the quark wave function systematically upwards but does not perform well for the mass function.