We present the International Lattice Data Grid (ILDG), a loosely federated grid of grids for sharing data from Lattice Quantum Chromodynamics (LQCD) simulations. The ILDG comprises of metadata, file format and web-service standards, which can be used to wrap regional data-grid interfaces, allowing seamless access to catalogues and data in a diverse set of collaborating regional grids. We discuss the technological underpinnings of the ILDG, primarily the metadata and the middleware, and offer a critique of its various aspects with the hindsight of the design work and the first full year of production.Comment: 13 page

The decay constants of B, D and K mesons are computed in quenched lattice QCD at two different values of the coupling. The action and operators are O(a) improved with non-perturbative coefficients. The results are f B = 195(6) +24 −23 MeV, f D = 206(4) +17 −10 MeV, f Bs = 220(6) +23 −28 MeV, f Ds = 229(3) +23 −12 MeV and f K = 150(3) +12 − 8MeV. Systematic errors are discussed in detail. Results for vector decay constants, flavour symmetry breaking ratios of decay constants, the pseudoscalar-vector mass splitting and D meson masses are also presented.

The spectrum of orbitally excited D s mesons is computed in the continuum limit of quenched lattice QCD. The results are consistent with the interpretation that the narrow resonance in the D s π 0 channel discovered by the BABAR Collaboration is a J P = 0 + cs meson. Furthermore, within statistical errors, the 1 + − 1 − and the 0 + − 0 − mass splittings are equal, in agreement with the chiral multiplet structure predicted by heavy hadron chiral effective theory. On our coarsest lattice we present results from the first study of orbitally excited D s mesons with two flavors of dynamical quarks, with mass slightly larger than the strange quark mass. These results are consistent with the quenched data.

We present results from quenched lattice QCD for the form factors for the decay B → ρlν. The calculations are performed using a nonperturbatively improved action and operators at two values of the lattice spacing. The bottom quark mass is reached by extrapolation from simulations performed with heavy quark masses around the charm mass. Our primary result is for the partially integrated decay rate Γ PI over the range 12.7 GeV 2 < q 2 < 18.2 GeV 2 :Γ PI = 4.9 +12 −10 + 0 −14 × 10 12 s −1 |V ub | 2 .

We present the results of a lattice computation of the form factors for B 0 → π − l + ν l decays near zero-recoil. These results will allow a determination of the CKM matrix element |V ub | when measurements of the differential decay rate become available. We also provide models for extrapolation of the form factors and rate to the full recoil range. Our computation is performed in the quenched approximation to QCD on a 24 3 × 48 lattice at β = 6.2, using a non-perturbatively O(a)-improved action. The masses of all light valence quarks involved are extrapolated to their physical values.12.15Hh 12.38Gc 13.20He