Unquenched quark propagator in Landau gauge

TL;DR

This paper reports an unquenched lattice QCD calculation of the quark propagator in Landau gauge, analyzing sea quark effects with improved staggered fermions on a sizable lattice.

Contribution

It provides the first unquenched calculation of the quark propagator in Landau gauge using 2+1 flavors of dynamical quarks with improved staggered action.

Findings

Sea quark effects on the quark propagator are investigated.

The quark mass and renormalization functions are computed for various quark masses.

The study accesses lower momenta than previous quenched studies.

Abstract

We present an unquenched calculation of the quark propagator in Landau gauge with 2+1 flavors of dynamical quarks. We use configurations generated with an improved staggered (``Asqtad'') action by the MILC collaboration. This quark action has been seen to have excellent rotational symmetry and scaling properties in the quenched quark propagator. Quenched and dynamical calculations are performed on a $20^3\times 64$ lattice with a nominal lattice spacing of $a = 0.125$ fm. The matched quenched and dynamical lattices allow us to investigate the relatively subtle sea quark effects, and even in the quenched case the physical volume of these lattices gives access to lower momenta than our previous study. We calculate the quark mass function and renormalization function for a variety of valence and sea quark masses.