1,137 research outputs found

    The Equation of State for QCD with 2+1 Flavors of Quarks

    Full text link
    We report results for the interaction measure, pressure and energy density for nonzero temperature QCD with 2+1 flavors of improved staggered quarks. In our simulations we use a Symanzik improved gauge action and the Asqtad O(a2)O(a^2) improved staggered quark action for lattices with temporal extent Nt=4N_t=4 and 6. The heavy quark mass msm_s is fixed at approximately the physical strange quark mass and the two degenerate light quarks have masses mud=0.1msm_{ud} =0.1m_s or 0.2ms0.2m_s. The calculation of the thermodynamic observables employs the integral method where energy density and pressure are obtained by integration over the interaction measure.Comment: 6 pages, 1 figure, 3 tables, contribution to the XXIIIrd International Symposium on Lattice Field Theory, 25-30 July 2005, Trinity College, Dublin, Irelan

    More evidence of localization in the low-lying Dirac spectrum

    Full text link
    We have extended our computation of the inverse participation ratio of low-lying (asqtad) Dirac eigenvectors in quenched SU(3). The scaling dimension of the confining manifold is clearer and very near 3. We have also computed the 2-point correlator which further characterizes the localization.Comment: presented at Lattice2005(Topology and Confinement), Dublin, July 25-30, 2005, 6 pages, 3 figures, to appear in Proceedings of Scienc

    Pressure Modulator Radiometer (PMR) tests

    Get PDF
    The pressure modulator technique was evaluated for monitoring pollutant gases in the Earth's atmosphere of altitude levels corresponding to the mid and lower troposphere. Using an experimental set up and a 110 cm sample cell, pressure modulator output signals resulting from a range of gas concentrations in the sample cell were examined. Then a 20 cm sample cell was modified so that trace gas properties in the atmosphere could be simulated in the laboratory. These gas properties were measured using an infrared sensor

    Update on pi and K Physics

    Full text link
    We present an update of the MILC studies of the physics of light pseudoscalars using improved staggered fermions. New runs at lighter quark mass, as well as increased statistics for older sets, are enabling us to improve the results for decay constants in full QCD. In addition, we have analyzed quenched runs at two different lattice spacings. This makes possible a test of the applicability of staggered chiral perturbation theory in a different context.Comment: presented at Lattice2005(Hadron Spectrum), Dublin, July 25-30, 2005, 6 pages, 4 figures, to appear in Proceedings of Scienc

    Predictions from Lattice QCD

    Get PDF
    In the past year, we calculated with lattice QCD three quantities that were unknown or poorly known. They are the q2q^2 dependence of the form factor in semileptonic DKlνD\to Kl\nu decay, the decay constant of the DD meson, and the mass of the BcB_c meson. In this talk, we summarize these calculations, with emphasis on their (subsequent) confirmation by experiments.Comment: v1: talk given at the International Conference on QCD and Hadronic Physics, Beijing, June 16-20, 2005; v2: poster presented at the XXIIIrd International Symposium on Lattice Field Theory, Dublin, July 25-3

    A fast vertical trajectory prediction method for air traffic management, and relevant ATM system

    Get PDF
    The invention concerns a method and system for the prediction of aircrafts vertical trajectory, in particular for Air Traffic Management, comprising the following flight calculation modules: Take-off; Climb; Cruise; Descent; and Landing, corresponding to the relevant flight phases, wherein: the calculation of the predicted aircraft trajectory is effected by using a set of TEM equations comprising, as output variables, the vertical rate of climb or descent, the true air speed, the energy share factor, the thrust and the drag, the mass of the aircraft modeled as point-mass, and comprising, as inpu variables, the Mach number depending on true air speed and temperature and altitude, the gravity acceleration, and the fuel flow, and the flight path angle; the calculation of the predicted aircraft trajectory for Cruise phase, wherein only the mass is varying, is performed by using the following analytical solution to said set of TEM equations

    Charmed meson decay constants in three-flavor lattice QCD

    Full text link
    We present the first lattice QCD calculation with realistic sea quark content of the D^+ meson decay constant f_{D^+}. We use the MILC Collaboration's publicly available ensembles of lattice gauge fields, which have a quark sea with two flavors (up and down) much lighter than a third (strange). We obtain f_{D^+} = 201 +/- 3 +/- 17 MeV, where the errors are statistical and a combination of systematic errors. We also obtain f_{D_s} = 249 +/- 3 +/- 16 MeV for the D_s meson.Comment: note added on recent CLEO measurement; PRL versio
    corecore