Heavy-light decay constants using clover valence quarks and three flavors of dynamical improved staggered quarks

Starting in 2001, the MILC Collaboration began a large scale calculation of heavy-light meson decay constants using clover valence quarks on esembles of three flavor configurations. For the coarse configurations, with a = 0.12 fm, eight combinations of dynamical light and strange quarks have been analyzed. For the fine configurations, with a = 0.09 fm, three combinations of quark masses are studied. Since we last reported on this calculation, statistics have been increased on the fine ensembles, and, more importantly, a preliminary value fir the perturbative renormalization of the axial-vector current has become available. Thus, results for f_B, f_Bs, f_D and f_Ds can, in principle, be calculated in MeV, in addition to decay-constant ratios that were calculated previously.