4,990 research outputs found

    Poultry

    Get PDF
    Getting winter eggs from hens / D. C. Kennard and V. D. Chamberlin -- The protein requirements of growing pullets / R. M. Bethke, Paul R. Record and D. C. Kennard -- Coarse versus fine mash / D. C. Kennard -- Chicken vices / D. C. Kennard -- Tipping the beaks / D. C. Kennard -- Use of woven wire in poultry keeping -- Sun parlors for chick

    Measurement of the strong coupling alpha_S from the three-jet rate in e+e- - annihilation using JADE data

    Get PDF
    We present a measurement of the strong coupling alpha_S using the three-jet rate measured with the Durham algorithm in e+e- -annihilation using data of the JADE experiment at centre-of-mass energies between 14 and 44 GeV. Recent theoretical improvements provide predictions of the three-jet rate in e+e- -annihilation at next-to-next-to-leading order. In this paper a measurement of the three-jet rate is used to determine the strong coupling alpha_s from a comparison to next-to-next-to-leading order predictions matched with next-to-leading logarithmic approximations and yields a value for the strong coupling alpha_S(MZ) = 0.1199+- 0.0010 (stat.) +- 0.0021 (exp.) +- 0.0054 (had.) +- 0.0007 (theo.) consistent with the world average.Comment: 27 pages, 8 figure

    BˉXsγ\bar{B}\to X_s \gamma in the Two Higgs Doublet Model up to Next-to-Next-to-Leading Order in QCD

    Get PDF
    We compute three-loop matching corrections to the Wilson coefficients C7C_7 and C8C_8 in the Two Higgs Doublet Model by applying expansions for small, intermediate and large charged Higgs boson masses. The results are used to evaluate the branching ratio of BˉXsγ\bar{B}\to X_s \gamma to next-to-next-to leading order accuracy, and to determine an updated lower limit on the charged Higgs boson mass. We find \mhplus \ge 380 GeV at 95% confidence level when the recently completed BABAR data analysis is taken into account. Our results for the charged Higgs contribution to the branching ratio exhibit considerably weaker sensitivity to the matching scale μ0\mu_0, as compared to previous calculations.Comment: 20 pages, 15 figures; v2: minor modifications, matches published version in JHE

    Stringent constraints on the scalar K pi form factor from analyticity, unitarity and low-energy theorems

    Get PDF
    We investigate the scalar K pi form factor at low energies by the method of unitarity bounds adapted so as to include information on the phase and modulus along the elastic region of the unitarity cut. Using at input the values of the form factor at t=0 and the Callan-Treiman point, we obtain stringent constraints on the slope and curvature parameters of the Taylor expansion at the origin. Also, we predict a quite narrow range for the higher order ChPT corrections at the second Callan-Treiman point.Comment: 5 pages latex, uses EPJ style files, 3 figures, replaced with version accepted by EPJ

    A Precision Calculation of the Next-to-Leading Order Energy-Energy Correlation Function

    Get PDF
    The O(alpha_s^2) contribution to the Energy-Energy Correlation function (EEC) of e+e- -> hadrons is calculated to high precision and the results are shown to be larger than previously reported. The consistency with the leading logarithm approximation and the accurate cancellation of infrared singularities exhibited by the new calculation suggest that it is reliable. We offer evidence that the source of the disagreement with previous results lies in the regulation of double singularities.Comment: 6 pages, uuencoded LaTeX and one eps figure appended Complete paper as PostScript file (125 kB) available at: http://www.phys.washington.edu/~clay/eecpaper1/paper.htm

    Manifestation of Sea Quark Effects in the Strong Coupling Constant in Lattice QCD

    Get PDF
    We demonstrate that sea quark effects of a magnitude expected from renormalization group considerations are clearly visible in the strong coupling constant measured in current full QCD simulations. Building on this result an estimate of αMS(5)(MZ)\alpha_{\overline{MS}}^{(5)}(M_Z) is made employing the charmonium 1S1P1S-1P mass splitting calculated on full QCD configurations generated with two flavors of dynamical Kogut-Susskind quarks to fix the scale.Comment: 10 pages + 2 figures(postscript files), Latex files, compressed, uuencode tar file, UTHEP-28

    Renormalization scale uncertainty in tne DIS 2+1 jet cross-section

    Get PDF
    The deep inelastic scattering 2+1 jet cross- section is a useful observable for precision tests of QCD, e.g. measuring the strong coupling constant alpha(s). A consistent analysis requires a good understanding of the theoretical uncertainties and one of the most fundamental ones in QCD is due to the renormalization scheme and scale ambiguity. Different methods, which have been proposed to resolve the scale ambiguity, are applied to the 2+1 jet cross-section and the uncertainty is estimated. It is shown that the uncertainty can be made smaller by choosing the jet definition in a suitable way.Comment: 24 pages, uuencoded compressed tar file, DESY 94-082, TSL-ISV-94-009

    Elastic π+p\pi^{+}p and π+π+\pi^{+}\pi^{+} scattering at LHC

    Full text link
    We discuss the possibility of measuring leading neutron production at the LHC. These data could be used to extract from it π+p\pi^+ p and π+π+\pi^+\pi^+ cross-sections. In this note we give some estimates for the case of elastic cross-sections and discuss related problems and prospects.Comment: 26 pages, 25 figures, to be published, minor text correction

    Unified Universal Seesaw Models

    Full text link
    A set of Grand Unified Theories based upon the gauge groups SU(5)_\L \times SU(5)_\R, SO(10)_\L \times SO(10)_\R and SU(4)_\C \times SU(4)_\L \times SU(4)_\R is explored. Several novel features distinguish these theories from the well-known SU(5)SU(5), SO(10)SO(10) and SU(4)_\C \times SU(2)_\L \times SU(2)_\R models which they generalize. Firstly, Standard Model quarks and leptons are accompanied by and mix with heavy SU(2)_\L \times SU(2)_\R singlet partners. The resulting fermion mass matrices are seesaw in form. Discrete parity symmetries render the determinants of these mass matrices real and eliminate CP violating gauge terms. The unified seesaw models consequently provide a possible resolution to the strong CP problem. Secondly, \sinsq at the unification scale is numerically smaller than the experimentally measured ZZ scale value. The weak angle must therefore increase as it evolves down in energy. Finally, proton decay is suppressed by small seesaw mixing factors in all these theories.Comment: 22 pages with 2 figures not included but available upon request, CALT-68-185

    Fluorine in animal nutrition

    Get PDF
    corecore