Perturbative Matching of the NRQCD Heavy-Light Axial Current

A one-loop matching calculation between Lattice NRQCD and full QCD for the heavy-light axial current is described and the effects on f_B are discussed.Comment: Talk presented at Lattice '97, Edinburgh, July 1997. 3 LaTeX pages plus 2 postscript figures. Uses espcrc2.st

Perturbative Matching of Heavy-Light Currents with NRQCD Heavy Quarks

We present further results for one-loop matching of heavy-light axial and vector currents between continuum QCD and a lattice theory with NRQCD heavy quarks and massless clover quarks.Comment: LATTICE98(heavyqk

Matching lattice and continuum axial-vector and vector currents with nonrelativistic QCD and highly improved staggered quarks

We match the continuum and lattice axial-vector and vector currents at one loop in perturbation theory. For the heavy quarks we use the nonrelativistic QCD (NRQCD) action and for the light quarks the highly improved staggered quark (HISQ) action. We present results for both massless and massive HISQ quarks and as part of the matching procedure we include a discussion of the one loop HISQ renormalization parameters. DOI: 10.1103/PhysRevD.87.03401

Bs→KℓνB_s \to K \ell \nu form factors from lattice QCD

We report the first lattice QCD calculation of the form factors for the standard model tree-level decay $B_s\to K \ell\nu$. In combination with future measurement, this calculation will provide an alternative exclusive semileptonic determination of $|V_{ub}|$. We compare our results with previous model calculations, make predictions for differential decay rates and branching fractions, and predict the ratio of differential branching fractions between $B_s\to K\tau\nu$ and $B_s\to K\mu\nu$. We also present standard model predictions for differential decay rate forward-backward asymmetries, polarization fractions, and calculate potentially useful ratios of $B_s\to K$ form factors with those of the fictitious $B_s\to\eta_s$ decay. Our lattice simulations utilize NRQCD $b$ and HISQ light quarks on a subset of the MILC Collaboration's $2+1$ asqtad gauge configurations, including two lattice spacings and a range of light quark masses.Comment: 24 pages, 21 figures; Ver. 2 matches published versio