Further results on O( a) improved lattice QCD to one-loop order of perturbation theory

We present results at one-loop order of perturbation theory for various improvement coefficients in on-shell O( a) improved lattice QCD. In particular we determine the additive counterterm required for on-shell improvement of the isovector vector current. Employing a general mass-independent renormalization scheme we also obtain the coefficients of the O( a) counterterms which are proportional to the quark mass in the improved isovector pseudo-scalar, axial vector and vector operators. In the latter case a comparison with a recent non-perturbative study is made.