Non-perturbative renormalization of the static vector current and its O(a)-improvement in quenched QCD

Abstract

We carry out the renormalization and the Symanzik O(a)-improvement programme for the static vector current in quenched lattice QCD. The scale independent ratio of the renormalization constants of the static vector and axial currents is obtained non-perturbatively from an axial Ward identity with Wilson-type light quarks and various lattice discretizations of the static action. The improvement coefficients cVstat and bVstat are obtained up to O(g_0^4)-terms by enforcing improvement conditions respectively on the axial Ward identity and a three-point correlator of the static vector current. A comparison between the non-perturbative estimates and the corresponding one-loop results shows a non-negligible effect of the O(g_0^4)-terms on the improvement coefficients but a good accuracy of the perturbative description of the ratio of the renormalization constants.