3,591 research outputs found

    Experimental limits on New Physics from charm decay

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    Recent measurements in the charm sector are reviewed, concentrating on results which are sensitive to New Physics effects. The scope of the presentation includes D0-D0bar mixing searches, a CPT / Lorentz invariance study, and a range of searches for rare and forbidden decays. Results from the BaBar, Belle, CDF, CLEO, and FOCUS collaborations are presented, including an important first observation.Comment: 14 pages, 5 tables, 17 figures. Invited talk presented at the 21st International Symposium On Lepton And Photon Interactions At High Energies (LP03) 11-16 August 2003, Batavia, Illinois. To appear in the proceedings of the symposiu

    Factors associated with Anaplasma spp. seroprevalence among dogs in the United States

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    Background Dogs in the United States are hosts to a diverse range of ticks and tick-borne pathogens, including A. phagocytophilum, an important emerging canine and human pathogen. Previously, a Companion Animal Parasite Council (CAPC)-sponsored workshop proposed factors purported to be associated with the infection risk for tick-transmitted pathogens in dogs in the United States, including climate conditions, socioeconomic characteristics, local topography, and vector distribution. Methods Approximately four million test results from routine veterinary diagnostic tests from 2011–2013, which were collected on a county level across the contiguous United States, are statistically analyzed with the proposed factors via logistic regression and generalized estimating equations. Spatial prevalence maps of baseline Anaplasma spp. prevalence are constructed from Kriging and head-banging smoothing methods. Results All of the examined factors, with the exception of surface water coverage, were significantly associated with Anaplasma spp. prevalence. Overall, Anaplasma spp. prevalence increases with increasing precipitation and forestation coverage and decreases with increasing temperature, population density, relative humidity, and elevation. Interestingly, socioeconomic status and deer/vehicle collisions were positively and negatively correlated with canine Anaplasma seroprevalence, respectively. A spatial map of the canine Anaplasma hazard is an auxiliary product of the analysis. Anaplasma spp. prevalence is highest in New England and the Upper Midwest. Conclusions The results from the two posited statistical models (one that contains an endemic areas assumption and one that does not) are in general agreement, with the major difference being that the endemic areas model estimates a larger prevalence in Western Texas, New Mexico, and Colorado. As A. phagocytophilum is zoonotic, the results of this analysis could also help predict areas of high risk for human exposure to this pathogen

    The trigger system of the NOMAD experiment

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    The NOMAD trigger system is described in the present paper. It is made up of a largearea plastic scintillator veto system, two trigger scintillator planes inside a 0.4~Tmagnetic field and their associated trigger electronics. Special features of the systemconsist of the use of proximity mesh photomultipliers which allow the trigger scintillators to operate in the magnetic field, and the use of custom-built VME moduleswhich perform the trigger logic decisions, the signal synchronisation and gate generation,event counting and livetime calculations. This paper also includes a description of each of the NOMAD triggers, with their calculated and measured rates, efficiencies and livetimes

    Search for the exotic Θ+\Theta^+ resonance in the NOMAD experiment

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    A search for exotic Theta baryon via Theta -> proton +Ks decay mode in the NOMAD muon neutrino DIS data is reported. The special background generation procedure was developed. The proton identification criteria are tuned to maximize the sensitivity to the Theta signal as a function of xF which allows to study the Theta production mechanism. We do not observe any evidence for the Theta state in the NOMAD data. We provide an upper limit on Theta production rate at 90% CL as 2.13 per 1000 of neutrino interactions.Comment: Accepted to European Physics Journal

    Observation of X(3872)J/ψγX(3872)\to J/\psi \gamma and search for X(3872)ψγX(3872)\to\psi'\gamma in B decays

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    We report a study of B(J/ψγ)KB\to (J/\psi \gamma) K and B(ψγ)KB\to (\psi' \gamma)K decay modes using 772×106772\times 10^{6} BBˉB\bar{B} events collected at the \Upsilon(4S)resonancewiththeBelledetectorattheKEKBenergyasymmetric resonance with the Belle detector at the KEKB energy-asymmetric e^+ e^-collider.Weobserve collider. We observe X(3872) \to J/\psi \gammaandreportthefirstevidencefor and report the first evidence for \chi_{c2} \to J/\psi \gammain in B\to (X_{c\bar{c}}\gamma) Kdecays,whileinasearchfor decays, while in a search for X(3872) \to \psi' \gammanosignificantsignalisfound.Wemeasurethebranchingfractions, no significant signal is found. We measure the branching fractions, \mathcal{B}(B^{\pm} \to X(3872) K^{\pm}) \mathcal{B}(X(3872) \to J/\psi\gamma) = (1.78^{+0.48}_{-0.44}\pm 0.12)\times 10^{-6},, \mathcal{B} (B^{\pm} \to\chi_{c2} K^{\pm})= (1.11^{+0.36}_{-0.34} \pm 0.09) \times 10^{-5},, \mathcal{B}(B^{\pm} \to X(3872) K^{\pm}) \mathcal{B}(X(3872) \to \psi'\gamma) < 3.45\times 10^{-6}$ (upper limit at 90% C.L.) and also provide upper limits for other searches.Comment: 6 pages, 3 figure

    Production properties of K*(892) vector mesons and their spin alignment as measured in the NOMAD experiment

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    First measurements of K*(892) mesons production properties and their spin alignment in nu_mu charged current (CC) and neutral current (NC) interactions are presented. The analysis of the full data sample of the NOMAD experiment is performed in different kinematic regions. For K*+ and K*- mesons produced in nu_mu CC interactions and decaying into K0 pi+/- we have found the following yields per event: (2.6 +/- 0.2 (stat.) +/- 0.2 (syst.))% and (1.6 +/- 0.1 (stat.) +/- 0.1 (syst.))% respectively, while for the K*+ and K*- mesons produced in nu NC interactions the corresponding yields per event are: (2.5 +/- 0.3 (stat.) +/- 0.3 (syst.))% and (1.0 +/- 0.3 (stat.) +/- 0.2 (syst.))%. The results obtained for the rho00 parameter, 0.40 +/- 0.06 (stat) +/- 0.03 (syst) and 0.28 +/- 0.07 (stat) +/- 0.03 (syst) for K*+ and K*- produced in nu_mu CC interactions, are compared to theoretical predictions tuned on LEP measurements in e+e- annihilation at the Z0 pole. For K*+ mesons produced in nu NC interactions the measured rho00 parameter is 0.66 +/- 0.10 (stat) +/- 0.05 (syst).Comment: 20 p
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