531 research outputs found
T-odd Asymmetry in W+jet Events at the LHC
W bosons produced at high transverse momentum in hadron collisions can have
polarization along the direction perpendicular to the production plane, which
is odd under na\ddot{\i}ve-T-reversal where both the three-momenta and
angular momenta are reversed. Perturbative QCD predicts non-zero polarization
at the one-loop level, which can be measured as parity-odd components in the
angular distribution of charged leptons from the decay of W bosons. We perform
a detector-level simulation with the generator MadGraph5_aMC@NLO, and
demonstrate that the asymmetry can be observed at the 8 TeV LHC with 20
fb of data. If confirmed, it will be the first experimental measurement
of the sign of the imaginary part of one-loop QCD amplitudes.Comment: 5 pages, 2 figure
Food safety control system of Chinese eel exports and its challenges
This paper analyzes factors associated with the rejection of products at ports of importer countries and remedial actions taken by producers in China. As an example, it uses one of the most competitive agro-food products of China: live and processed eels. This paper provides an overview of eel production and trade trends in China. In addition, it identifies the causes of port rejection of Chinese eel products as veterinary drug residues by examining the detailed case studies of export firms and the countermeasures taken by the government and firms
Electroweak Precision Measurements and the Minimal Supersymmetric Standard Model
We discuss supersymmetric contributions to the electroweak precision
measurements in the Minimal Supersymmetric Standard Model for two cases: the
quark-lepton universality violation in charged currents and
the ratio .
The recent experimental data suggest deviations from the Standard Model for
these observables, at the 1- level for the former and at more than
3- level for the latter. We analyze the non-oblique corrections from
the SUSY particles to explain these discrepancies. The observed non-zero
may be explained by relatively light sleptons, charginos and
neutralinos. Although the observed excess of can be explained by very
light scalar top and chargino for low , this interpretation is
severely constrained by the opening of exotic decay modes for the top quark.Comment: 11 pages, LaTeX, uses ptptex.sty, with uuencoded eps figures, Talk
given by Y. Yamada at Yukawa International Seminar (YKIS) '95 ``From the
Standard Model to Grand Unified Theories'', Kyoto, Japan, August 21--25,
1995. To appear in the Proceeding
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