Scaling and further tests of heavy meson decay constant determinations from nonrelativistic QCD - art. no. 034505

We present results for the B-s meson decay constant f(Bs) from simulations at three lattice spacings in the range a(-1) = 1.1 to 2.6 GeV using NRQCD h eavy quarks and clover light quarks in the quenched approximation. We study the scaling of this quantity and check the consistency between mesons deca ying from rest and from a state with a nonzero spatial momentum. The cancel lation of power law contributions that arise in the NRQCD formulation of he avy-light currents is discussed. On the coarsest lattice the D-s meson deca y constant f(Ds) is calculated. Our best values for the decay constants are given by f(Bs) = 187(4)(4)(11)(2)(7)(6) MeV and f(Ds) = 223(6)(31)(38)(23) (9)((+3)(-1)) MeV.