4,255 research outputs found

    Performance of a C4F8O Gas Radiator Ring Imaging Cherenkov Detector Using Multi-anode Photomultiplier Tubes

    Full text link
    We report on test results of a novel ring imaging Cherenkov (RICH) detection system consisting of a 3 meter long gaseous C4F8O radiator, a focusing mirror, and a photon detector array based on Hamamatsu multi-anode photomultiplier tubes. This system was developed to identify charged particles in the momentum range from 3-70 GeV/c for the BTeV experiment.Comment: 28 pages, 23 figures, submitted to Nuclear Instruments and Method

    QCD soft gluon exponentiation: YFS MC Approach

    Get PDF
    We develop and prove the theory of the QCD extension of the YFS Monte Carlo approach to higher order QED radiative corrections. As a corollary, a new approach to quantum gravity by one of us (B.F.L.W.) is illustrated. Semi-analytical results and preliminary explicit Monte Carlo data are presented for the processes p-bar p -> t-bar t + X at FNAL energies. We comment briefly on the implications of our results on the CDF/D0 observations and on RHIC/LHC physics.Comment: 4 pages, 2 figures, presented at ICHEP02 by BFL

    LHCb Alignment Strategy

    Get PDF
    In this note, we review the alignment strategy for the LHCb detector. We discuss the internal alignment stategy for each subdetector and the alignment of each of the subdetectors relative to one another

    Hadron Spectroscopy: Theory and Experiment

    Get PDF
    Many new results on hadron spectra have been appearing in the past few years thanks to improved experimental techniques and searches in new channels. New theoretical techniques including refined methods of lattice QCD have kept pace with these developments. Much has been learned about states made of both light (u, d, and s) and heavy (c, b) quarks. The present review treats light-quark mesons, glueballs, hybrids, particles with a single c or b quark, charmonium, and bottomonium states. Some prospects for further study are noted.Comment: 29 pages, 9 figures, to be published in Journal of Physics G. Further updating of reference

    Search for rare and forbidden decays of charm and charmed-strange mesons to final states h^+- e^-+ e^+

    Get PDF
    We have searched for flavor-changing neutral current decays and lepton-number-violating decays of D^+ and D^+_s mesons to final states of the form h^+- e^-+ e^+, where h is either \pi or K. We use the complete samples of CLEO-c open-charm data, corresponding to integrated luminosities of 818 pb^-1 at the center-of-mass energy E_CM = 3.774 GeV containing 2.4 x 10^6 D^+D^- pairs and 602 pb^-1 at E_CM = 4.170 GeV containing 0.6 x 10^6 D^*+-_s D^-+_s pairs. No signal is observed in any channel, and we obtain 90% confidence level upper limits on branching fractions B(D^+ --> \pi^+ e^+ e^-) < 5.9 x 10^-6, B(D^+ --> \pi^- e^+ e^+) K^+ e^+ e^-) < 3.0 x 10^-6, B(D^+ --> K^- e^+ e^+) \pi^+ e^+ e^-) < 2.2 x 10^-5, B(D^+_s --> \pi^- e^+ e^+) K^+ e^+ e^-) < 5.2 x 10^-5, and B(D^+_s --> K^- e^+ e^+) < 1.7 x 10^-5.Comment: 9 pages, available through http://www.lns.cornell.edu/public/CLNS

    Measurement of \cal{B}(D^+ --> mu^+ nu) and the Pseudoscalar Decay Constant fD+f_{D^+}

    Full text link
    In 60 pb-1 of data taken on the psi(3770) resonance with the CLEO-c detector, we find 8 D+ to mu+ nu event candidates that are mostly signal, containing only 1 estimated background. Using this statistically compelling sample, we measure preliminary values of B(D+ to mu+ nu) = (3.5 +- 1.4 +- 0.6)*10^{-4}, and determine f_{D+} =(201+- 41+- 17) MeV.Comment: 17 pages postscript, also available through http://www.lns.cornell.edu/public/CONF/2004/, Presented at ICHEP Aug 16-22,2004, Beijing, Chin

    Determination of the D0 -> K+pi- Relative Strong Phase Using Quantum-Correlated Measurements in e+e- -> D0 D0bar at CLEO

    Full text link
    We exploit the quantum coherence between pair-produced D0 and D0bar in psi(3770) decays to study charm mixing, which is characterized by the parameters x and y, and to make a first determination of the relative strong phase \delta between doubly Cabibbo-suppressed D0 -> K+pi- and Cabibbo-favored D0bar -> K+pi-. We analyze a sample of 1.0 million D0D0bar pairs from 281 pb^-1 of e+e- collision data collected with the CLEO-c detector at E_cm = 3.77 GeV. By combining CLEO-c measurements with branching fraction input and time-integrated measurements of R_M = (x^2+y^2)/2 and R_{WS} = Gamma(D0 -> K+pi-)/Gamma(D0bar -> K+pi-) from other experiments, we find \cos\delta = 1.03 +0.31-0.17 +- 0.06, where the uncertainties are statistical and systematic, respectively. In addition, by further including external measurements of charm mixing parameters, we obtain an alternate measurement of \cos\delta = 1.10 +- 0.35 +- 0.07, as well as x\sin\delta = (4.4 +2.7-1.8 +- 2.9) x 10^-3 and \delta = 22 +11-12 +9-11 degrees.Comment: 37 pages, also available through http://www.lns.cornell.edu/public/CLNS/2007/. Incorporated referee's comment

    Branching Fraction Measurements of psi(2S) Decay to Baryon-Antibaryon Final States

    Full text link
    Using 3.08 million psi(2S) decays observed in e^+e^- collisions by the CLEO detector, we present the results of a study of the psi(2S) decaying into baryon-antibaryon final states. We report the most precise measurements of the following eight modes: proton-antiproton, lambda-antilambda, Xi^- antiXi^-, Xi^0-antiXi^0 (first observation), Sigma+-antiSigma^+ (first observation), and Sigma^0-antiSigma^0, and place upper limits for the modes, Xi^0*-antiXi^0* and Omega^- antiOmega^-.Comment: 8 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2005/, submitted to PR
    corecore