Aspects of determining fBs: scaling and power-law divergences

Abstract

We present preliminary results for the decay constant of the Bs meson, fBs, at three values of beta=5.7, 6.0 and 6.2 using NRQCD and clover fermions for the heavy and light quarks respectively. As a consistency check the decay constant has also been extracted from the axial-vector current at finite momentum. In addition, we discuss the cancellation of O(alpha/(aM0)) terms and the remaining uncertainty in fBs from higher order divergences.