Numerical exploration of the RI/MOM scheme gauge dependence

Abstract

The gauge dependence of some fermion bilinear RI/MOM renormalization constants is studied by comparing data which have been gauge-fixed in two different realizations of the Landau gauge and in a generic covariant gauge. The very good agreement between the various sets of results and the theory indicates that the numerical uncertainty induced by the lattice gauge-fixing procedure is below the statistical errors of our data sample which is of the order of (1 ÷ 1.5)%.

Nonperturbative renormalization of composite operators with overlap fermions

“…Since gauge fixing is involved for the external quark state, there are concerns about the effects of Gribov copies on the numerical results of the renormalization procedure. A study of two different realization of the Landau gauge and a covariant gauge shows that the renormalization constants from these gauge fixings differ by less than the statistical errors of about 1%-1.5% level [37]. We shall thus assume that the potential uncertainty due to Gribov copies is at this 1%-1.5% level which is comparable to our statistical errors.…”