4,990 research outputs found
Poultry
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
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
in the Two Higgs Doublet Model up to Next-to-Next-to-Leading Order in QCD
We compute three-loop matching corrections to the Wilson coefficients
and 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 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 , 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
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
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
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 is made employing the
charmonium 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
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 and scattering at LHC
We discuss the possibility of measuring leading neutron production at the
LHC. These data could be used to extract from it and
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
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 , 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
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
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