B meson decay constants from NRQCD

Abstract We present quenched results for B meson decay constants using NRQCD b quarks and O (a) tadpole improved clover light quarks. For the first time, one-loop matching factors between lattice and continuum currents are incorporated through O (α/M ) taking operator mixing fully into account. This includes an important O (α a ) discretization correction to the heavy-light axial vector current. We find fB=147(11)(+8−12)(9)(6) MeV and fBs/fB=1.20(4)(+4−0).