Overlap Quark Propagator in Landau Gauge
  The properties of the quark propagator in Landau gauge in quenched QCD are examined for the overlap quark action. The overlap quark action satisfies the Ginsparg-Wilson relation and as such provides an exact lattice realization of chiral symmetry. This in turn implies that the quark action is free of ${\cal O}(a)$ errors. We present results using the standard Wilson fermion kernel in the overlap formalism on a $12^3\times 24$ lattice at a spacing of 0.125 fm. We obtain the nonperturbative momentum-dependent wavefunction renormalization function $Z(p)$ and the nonperturbative mass function $M(p)$ for a variety of bare masses. We perform a simple extrapolation to the chiral limit for these functions. We clearly observe the dynamically generated infrared mass and confirm the qualitative behavior found for the Landau gauge quark propagator in earlier studies. We attempt to extract the quark condensate from the asymptotic behavior of the mass function in the chiral limit. 
Fr\'ed\'eric D.R. Bonnet, Patrick O. Bowman, Derek B. Leinweber,   Anthony G. Williams and J. B. Zhang