B Physics with NRQCD: A Quenched Study

We present results on the spectrum of B mesons and heavy baryons, using a non-relativistic formulation for the heavy and a clover action for the light quark. We also discuss B meson decay constants and their dependency upon the heavy meson mass.Comment: 4 pages, uuencoded compressed postscript file, contribution to LATTICE 9

B Leptonic Decays and B- bar B Mixing with 2+1 Flavors of Dynamical Quarks

Calculations of B leptonic decays and B- bar B mixing using NRQCD heavy and Asqtad light valence quarks on the MILC dynamical configurations are described. Smearing has been implemented to substantially reduce the statistical errors of the matrix elements needed for the determination of f_B. The four-fermion matrix elements needed for the determination of f_{B_s}^2B_{B_s} have been calculated and a preliminary result is given.Comment: 3 pages, 3 figures, talk given at Lattice2004(heavy), Batavia, Illinois, 21-26 Jun 200

The B Meson Decay Constant from Unquenched Lattice QCD

We present determinations of the B meson decay constant f_B and of the ratio f_{B_s}/f_B using the MILC collaboration unquenched gauge configurations which include three flavors of light sea quarks. The mass of one of the sea quarks is kept around the strange quark mass, and we explore a range in masses for the two lighter sea quarks down to m_s/8. The heavy b quark is simulated using Nonrelativistic QCD, and both the valence and sea light quarks are represented by the highly improved (AsqTad) staggered quark action. The good chiral properties of the latter action allow for a much smoother chiral extrapolation to physical up and down quarks than has been possible in the past. We find f_B = 216(9)(19)(4) (6) MeV and f_{B_s} /f_B = 1.20(3)(1).Comment: 4 pages, 2 figure

The Upsilon spectrum and m_b from full lattice QCD

We show results for the Upsilon spectrum calculated in lattice QCD including for the first time vacuum polarization effects for light u and d quarks as well as s quarks. We use gluon field configurations generated by the MILC collaboration. The calculations compare the results for a variety of u and d quark masses, as well as making a comparison to quenched results (in which quark vacuum polarisation is ignored) and results with only u and d quarks. The b quarks in the Upsilon are treated in lattice Nonrelativistic QCD through NLO in an expansion in the velocity of the b quark. We concentrate on accurate results for orbital and radial splittings where we see clear agreement with experiment once u, d and s quark vacuum polarisation effects are included. This now allows a consistent determination of the parameters of QCD. We demonstrate this consistency through the agreement of the Upsilon and B spectrum using the same lattice bare b quark mass. A one-loop matching to continuum QCD gives a value for the b quark mass in full lattice QCD for the first time. We obtain m_b^{\bar{MS}}(m_b^{\bar{MS}}) = 4.4(3) GeV. We are able to give physical results for the heavy quark potential parameters, r_0 = 0.469(7) fm and r_1 = 0.321(5) fm. Results for the fine structure in the spectrum and the Upsilon leptonic width are also presented. We predict the Upsilon - eta_b splitting to be 61(14) MeV, the Upsilon^{\prime} - eta_b^{\prime} splitting as 30(19) MeV and the splitting between the h_b and the spin-average of the chi_b states to be less than 6 MeV. Improvements to these calculations that will be made in the near future are discussed.Comment: 24 pages, 19 figures. Version to be published. Minor changes made and typographical errors corrected. Experimental leptonic widths updated in section

Heavy-light meson decay constants from NRQCD: an analysis of the 1/M corrections

We present {\it preliminary} results for the decay constants of heavy-light mesons using NRQCD heavy and tadpole improved Clover light quarks. A comparison is made with data obtained using Wilson light quarks. We present an analysis of the 1/M corrections to the decay constants in the static limit and compare with the predictions of HQET.Comment: Contribution to Lattice 95, 4 pages uuencoded compressed postscript fil

Spectroscopy of Hadrons with b Quarks from Lattice NRQCD

Preliminary results from an extensive lattice calculation of the B, B_c, and \Upsilon spectrum at quenched \beta = 6.0 are presented. The study includes radially and orbitally excited mesons, and baryons containing b quarks. The b quarks are formulated using NRQCD; for light and c quarks, a tadpole-improved clover action is used.Comment: talk given at LATTICE98(heavyqk), 3 pages LaTeX, 2 Postscript figure