5,560 research outputs found

    ANTITRUST ENFORCEMENT AND AGRICULTURE

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    Industrial Organization,

    What Does the CMS Measurement of W-polarization Tell Us about the Underlying Theory of the Coupling of W-Bosons to Matter?

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    We discuss results of the CMS collaboration on the sensitivity of the LHC to WW boson polarisation in the process pp→W±+jet→e±jet+Ìžâ€‰âŁâ€‰âŁPTpp\to W^\pm + jet \to e^\pm jet+\not\!\!P_T using the LPL_P variable directly connected to ξ∗\theta^* angle of the outgoing lepton in the rest frame of the decaying WW. We have shown that for a given LPL_P, interference between different polarizations of the WW-boson is not negligible, and needs to be taken into account when considering the differential cross-section with respect to LPL_P. The LPL_P variable suggested by CMS collaboration is highly suitable variable to study LHC sensitivity to gV,gAg_V,g_A couplings of WW-boson to fermions. We note that the experimental sensitivity to W-boson polarization which is much higher than that to (gV,gAg_V,g_A) parameter space can be turned around and used to identify deviations from the Standard Model as a signal for new physics at the LHC.Comment: 11 pages, 8 figures. Updated to match the final version published in JHEP with updated figures and polished tex

    The Effect of a Rapidity Gap Veto on the Discrete BFKL Pomeron

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    We investigate the sensitivity of the discrete BFKL spectrum, which appears in the gluon Green function when the running coupling is considered, to a lower cut-off in the relative rapidities of the emitted particles. We find that the eigenvalues associated to each of the discrete eigenfunctions decrease with the size of the rapidity veto. The effect is stronger on the lowest eigenfunctions. The net result is a reduction of the growth with energy for the Green function together with a suppression in the regions with small transverse momentum.Comment: 10 pages, 3 figure

    Gluon Contributions to Parity-Violating Asymmetries in Polarized Proton-Proton Scattering

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    We report on a calculation of one-loop weak corrections to polarized quark-gluon scattering and the corresponding crossed channels. Such contributions are suppressed formally by one power of alpha_s relative to W- or Z-mediated quark-quark scattering, but would enable the spin asymmetry of the gluon distribution to contribute to parity-violating asymmetries that will soon be investigated in polarized proton-proton scattering experiments at RHIC. In certain kinematic regions, gluon contributions to parity-violating asymmetries can be as large as 10% of the tree-level W- and Z-exchanges in quark-quark scattering, but usually only where the parity-violating asymmetries are already small.Comment: LATEX 12 pages, 6 figure

    The Green Function for the BFKL Pomeron and the Transition to DGLAP Evolution

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    We consider the (process-independent) Green function for the BFKL equation in the next-to-leading order approximation, with running coupling, and explain how, within the semi-classical approximation, it is related to Green function of the Airy equation. The unique Green function is obtained from a combination of its required ultraviolet behaviour compatible with asymptotic freedom and an infrared limit phase imposed by the non-perturbative sector of QCD. We show that at sufficiently large gluon transverse momenta the corresponding gluon density matches that of the DGLAP analysis, whereas for relatively small values of the gluon transverse momentum the gluon distribution is sensitive to the Regge poles, whose positions are determined both by the non-pertubative QCD dynamics and physics at large transverse momenta.Comment: 14 pages, 2 figure

    Evolution and Devolution of Knowledge: A Tale of Two Biologies

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    Anthropological inquiry suggests that all societies classify animals and plants in similar ways. Paradoxically, in the same cultures that have seen large advances in biological science, citizenry's practical knowledge of nature has dramatically diminished. Here we describe historical, cross-cultural and developmental research on how people ordinarily conceptualize organic nature (folkbiology), concentrating on cognitive consequences associated with knowledge devolution. We show that results on psychological studies of categorization and reasoning from “standard populations” fail to generalize to humanity at large. Usual populations (Euro-American college students) have impoverished experience with nature, which yields misleading results about knowledge acquisition and the ontogenetic relationship between folkbiology and folkpsychology. We also show that groups living in the same habitat can manifest strikingly distinct behaviors, cognitions and social relations relative to it. This has novel implications for environmental decision making and management, including commons problems.

    Radiative Corrections to Chargino Production with Polarized Beams

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    We show that radiative corrections to chargino production in electron-positron annihilation with polarized beams can be large especially in the case of right handed electrons. In addition, there is some dependency on the squark masses that allows us to extract information about the squark spectrum from the chargino production.Comment: 4 pages, including 4 figures. Talk given at Linear Collider Workshop 2000--LCWS, Fermilab, Chicago, October 24-28, 200

    Radiatively Corrected Chargino Pair Production at LEP2

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    One-loop radiative corrections to the production cross section of a pair of light charginos in e+e- colliders are calculated within the MSSM. Top and bottom quarks and squarks are considered in the loops, and they are renormalized using the MS-bar scheme. If the center of mass energy is equal to 192 GeV, positive corrections typically of 10% to 15% are found when the squark mass parameters are equal to 1 TeV.Comment: 6 pages, including 5 figures. Latex. Talk given by M.A.D. at the International Workshop "Beyond the Standard Model: From Theory to Experiment", 13--17 October 1997, Valencia, Spai
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