Abstract:
We extend the application of axial Ward identities to
calculate $b_A, b_P$ and $b_T$, coefficients that give the
mass dependence of the renormalization constants of the
corresponding bilinear operators in the quenched theory. The
extension relies on using operators with non-degenerate
quark masses. It allows a complete determination of the O(a)
improvement coefficients for bilinears in the quenched
approximation using Ward Identities alone. Only the scale
dependent normalization constants $Z_P^0$ (or $Z_S^0$) and
$Z_T$ are undetermined. We present results of a pilot
numerical study using hadronic correlators.