Matching of the Heavy-Light Currents with NRQCD Heavy and Improved Naive Light Quarks

One-loop matching of heavy-light currents is carried out for a highly improved lattice action, including the effects of mixings with dimension 4 O(1/M) and O(a) operators. We use the NRQCD action for heavy quarks, the Asqtad improved naive action for light quarks, and the Symanzik improved glue action. These results are being used in recent heavy meson decay constant and semileptonic form factor calculations on the MILC dynamical configurations.Comment: 3 pages, 3 figures. Talk presented at Lattice2004(heavy

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

Heavy-Light Meson Semileptonic Decays with Staggered Light Quarks

We report on exploratory studies of heavy-light meson semileptonic decays using Asqtad light quarks, NRQCD heavy quarks and Symanzik improved glue on coarse quenched lattices. Oscillatory contributions to three-point correlators coming from the staggered light quarks are found to be handled well by Bayesian fitting methods. B meson decays to both the Goldstone pion and to one of the point-split non-Goldstone pions are investigated. One-loop perturbative matching of NRQCD/Asqtad heavy-light currents is incorporated.Comment: 3 pages, 3 postscript figures, Lattice2003(heavy

Can Your P2O5 Be Commercially Exploited?

World reserves of high-grade, high-quality phosphate rock are steadily decreasing. As a result, lower quality rock is being increasingly evaluated to determine its potential for commercial exploitation. It is well known that the chemical and mineralogical composition of phosphate rock varies widely from deposit to deposit, and therefore, the conditions for processing different phosphate rock types also varies. Unfortunately, most early stage phosphate feasibility studies tend to focus on the P2O5 content and neglect the other chemical constituents or impurities in the rock. It is the remainder of the chemical constituents that often define the quality of the P2O5 concentrate and its potential for conversion to phosphate fertilizers. Typically, when evaluating phosphate ore and subsequent concentrate as a raw material, the first step is to analyze the composition (P2O5 and impurities) to gain a preliminary understanding of how the rock may behave in downstream chemical processing or as a direct application fertilizer. In addition to %P2O5, the following chemical constituents, at a minimum, should be evaluated when assessing the suitability of any phosphate rock: Calcium (%CaO) Magnesium (%MgO) Iron (%Fe2O3) Aluminum (%Al2O3) Silica (%SiO2) Chlorine (%Cl) Fluorine (%F) Carbon Dioxide (CO2) and Organics Sulfides Sodium (Na2O) and Potassium (K2O) Heavy metals, rare earths, and other elements. Once the above chemical analyses of a representative phosphate rock product are known, it is often possible to predict the suitability of the rock as feed for conventional wet process phosphoric acid production. However, given the vast range in which these chemical constituents can be present, acidulation pilot plant testing must be carried out during the feasibility study project phase in order to properly assess the deportment of these constituents into the acid and/or gypsum. This paper is presented to give a general understanding of the conventional wet acid process for conversion (acidulation) of phosphate rock as it relates to the presence and concentration of the major chemical constituents usually associated with phosphate rocks. Five case studies are presented

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

B_K from improved staggered quarks

We compare calculations of B_K with improved staggered quarks (HYP, Asqtad) and demonstrate the improved scaling behaviour that this gives rise to over previous calculations with unimproved staggered quarks. This enables us to perform the calculation of B_K on the MILC dynamical configurations (n_f=2+1), for which we give preliminary results.Comment: 3 pages, 3 figures. Talk presented at Lattice 2004(weak), Fermilab, June 21-26, 200

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