Non-perturbative renormalization of vector and axial vector currents in quenched QCD for a renormalization group improved gauge action

Renormalization constants of vector (Zv) and axial-vector (ZA) currents are determined non-perturbatively in quenched QCD for an RG-improved gauge action and a tadpole-improved clover quark action using the Schroedinger functional method. Meson decay constants pρ and fπ show much better scaling when Zv and ZpA estimated for infinite physical volume are used instead of Z-factors from tadpole-improved one-loop perturbation theory