Nonperturbative renormalization in the RI-SMOM Scheme and gribov uncertainty in the RI-MOM scheme for staggered bilinears

Abstract

We present results of renormalization factors for bilinear operators obtained using the nonperturbative renormalization method (NPR) in the RI-SMOM schemes. The operators are constructed using HYP staggered quarks on the MILC asqtad lattice (Nf = 2+1). We compare results in the RI-SMOM schemes with those in the RI-MOM scheme for the V ⊗ S and S ⊗ S operators. Since we use Landau gauge fixing, we study the effect of Gribov ambiguity on the wave function renormalization Zq in the RI-MOM scheme. We find that the Gribov uncertainty is negligibly small for Zq in the RI-MOM scheme.