Viability of perturbative renormalization factors in lattice QCD calculation of theK0-K¯0mixing matrix

Validity of perturbative estimation of renormalization factors in weak matrix element calculations in lattice QCD is examined for the ${\mathit{K}}^{0\mathrm{-}}$K${\mathrm{¯}}^0$ mixing matrix by comparing results for gauge invariant and noninvariant operators. A large disagreement found for uncorrected results for the two cases is shown to be removed by the one-loop renormalization factor. This indicates that the large scaling violation in the mixing matrix previously reported is not due to an artifact of prescription of lattice calculations. Our estimate of B${\mathrm{^}}_{\mathit{K}}$ for the continuum in quenched QCD is 0.61(13)–0.83(7).