Overlap quark propagator in Landau and Laplacian gauges

The properties of the momentum space quark propagator in Landau gauge and Gribov copy free Laplacian gauge are studied for the overlap quark action in quenched lattice QCD. Numerical calculations are done on a 163 × 32 lattice with lattice spacing a = 0.093 fm. We have calculated the nonperturbative momentum-dependent wave function renormalization function Z(q) and the nonperturbative mass function M(p) for a variety of bare quarks masses and perform a simple linear extrapolation to the chiral limit. We focus on the comparison of the behavior of Z(q) and M(p) in the chiral limit in the two gauge fixing schemes. We find that the mass functions M(p) are very similar for the two gauges while the wave-function renormalization function Z(q) is more strongly infrared suppressed in the Laplacian gauge than in the Landau gauge.