6,037 research outputs found

    Radiative neutrino decay and CP-violation in R-parity violating supersymmetry

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    We calculate the radiative decay amplitude for Majorana neutrinos in trilinear R-parity violating supersymmetric framework. Our results make no assumption regarding the masses and mixings of fermions and sfermions. The results obtained are exemplary for generic models with loop-generated neutrino masses. Comparison of this amplitude with the neutrino mass matrix shows that the two provide independent probes of CP-violating phases.Comment: Latex, uses axodraw, 14 pages (small changes implemented

    New Signatures of Squarks

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    When the gluino is light and long lived, missing energy is a poor signature for both squarks and gluinos. Instead, SqSqS_q S_q^* production in e+ee^+ e^- and ppˉp \bar{p} collisions characteristically results in events with 4\ge 4 jets. Methods are proposed for deciding whether an observed excess of 4-jet events is due to SqSqS_q S_q^* production. The recent report by ALEPH of observation of 14 4-jet events when 7 were expected is discussed.Comment: 12/22/95 version (put on net 1/1/96) elaborates remarks on squarks as possible source of ALEPH 4-jet excess and adds a ref. latex, 10 pages (including 1 figure), uufile

    Upper bounds on all R-parity-violating \lambda\lambda'' combinations from proton stability

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    In an R-parity-violating supersymmetric theory, we derive upper bounds on all the \lambda''_{ijk}\lambda_{i'j'k'}-type combinations from the consideration of proton stability, where \lambda''_{ijk} are baryon-number-violating couplings involving three baryonic fields and \lambda_{i'j'k'} are lepton-number-violating couplings involving three leptonic fields.Comment: 5 pages, Latex, uses axodraw.sty; minor changes in the text. Final versio

    Effect of Fibonacci Modulation On Superconductivity

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    We have studied finite-sized single band models with short range pairing interactions between electrons in presence of diagonal Fibonacci modulation in one dimension. Two models, namely the attractive Hubbard model and the Penson-Kolb model, have been investigated at half-filling at zero temperature by solving the Bogoliubov-de Gennes equations in real space within a mean field approximation. The competition between ``disorder'' and the pairing interaction leads to a suppression of superconductivity (of usual pairs with zero centre-of-mass momenta) in the strong-coupling limit while an enhancement of the pairing correlation is observed in the weak-coupling regime for both the models. However, the dissimilarity of the pairing mechanisms in these two models brings about notable difference in the results. The extent to which the bond ordered wave and the η\eta-paired (of pairs with centre-of-mass momenta = π\pi) phases of the Penson-Kolb model are affected by the disorder has also been studied in the present calculation. Some finite size effects are also identified.Comment: 14 pages, 13 figure

    FACTORS INFLUENCING RATES OF ADOPTION OF TRICHOMONIASIS VACCINE BY NEVADA RANGE CATTLE PRODUCERS

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    Tritrichimonas foetus vaccine has been marketed since 1989 to combat the trichomoniasis disease that causes reproductive failure and considerable economic loss to Nevada ranchers. An ex post technology adoption model is estimated to examine the possible adoption rate, to identify the factors that may influence the adoption behavior, and to test how the probability of adoption for five possible adopter groups would change due to changes in various ranch specific factors. Results indicate that use of computers, veterinary checkup of herd, and herd size influence the probability of adoption. Model results show that cooperative extension programs enhance the rate of adoption.Livestock Production/Industries,

    A Non-supersymmetric Interpretation of the CDF e+e-\gamma\gamma + missing E_T Event

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    The \eegg event reported recently by the CDF Collaboration has been interpreted as a signal of supersymmetry in several recent papers. In this article, we report on an alternative non-supersymmetric interpretation of the event using an extension of the standard model which contains new physics at the electroweak scale that does not effect the existing precision electroweak data. We extend the standard model by including an extra sequential generation of fermions, heavy right-handed neutrinos for all generations and an extra singly charged SU(2)-singlet Higgs boson. We discuss possible ways to discriminate this from the standard supersymemtric interpretations.Comment: 7 pages, Latex, no figure

    Constraining R-parity violating couplings from B --> PP decays using QCD improved factorization method

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    We investigate the role of R-parity violating interaction in the non-leptonic decays of B mesons into two light mesons B --> PP. The decay amplitudes are calculated using the QCD improved factorization method. Using the combined data on B decays from BaBar, Belle and CLEO, we obtain strong constraints on the various products of R-parity violating couplings. Many of these new constraints are stronger than the existing bounds.Comment: 19 pages including two eps figure

    Evidence for enhanced desorption of hydrogen atoms from a Si 100 surface induced by slow highly charged ions

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    We report evidence for an enhanced desorption of hydrogen atoms from a Si 100 surface bombarded by 30 keV Xeq q 6?22 ions. The measured desorption yield amounts to 0.76 and 2.2 hydrogen atoms per incident Xe10 and Xe18 ion, respectively. For understanding the behaviour of hydrogen desorption from Si, another experiment was carried out to see the hydrogen signals as a function of time for about 140 min after deliberately introducing hydrogen into the target chamber and then shut off the valve. The results are discussed in the light of potential sputtering which essentially dominates for ions at higher charge states and the interpretation is supported by theoretical estimates

    Relativistic Viscous Fluid Dynamics and Non-Equilibrium Entropy

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    Fluid dynamics corresponds to the dynamics of a substance in the long wavelength limit. Writing down all terms in a gradient (long wavelength) expansion up to second order for a relativistic system at vanishing charge density, one obtains the most general (causal) equations of motion for a fluid in the presence of shear and bulk viscosity, as well as the structure of the non-equilibrium entropy current. Requiring positivity of the divergence of the non-equilibrium entropy current relates some of its coefficients to those entering the equations of motion. I comment on possible applications of these results for conformal and non-conformal fluids.Comment: 25 pages, no figures; v2: matches published versio
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