36 research outputs found

    New Results from CLEO-II on Hadronic Decays of the Tau Lepton

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    Results on semi-hadronic decays of the τ\tau lepton are presented, from studies of e+ee^+e^- annihilation data obtained at the Cornell Electron Storage Ring with the CLEO-II detector. Branching fractions have been measured for decays to two, three and four hadrons, namely τ ⁣ ⁣ ⁣ντhπ0\tau^-\!\!\rightarrow\! \nu_\tau h^-\pi^0, τ ⁣ ⁣ ⁣ντhh+h\tau^-\!\!\rightarrow\! \nu_\tau h^-h^+h^-, and τ ⁣ ⁣ ⁣ντhh+hπ0\tau^-\!\!\rightarrow\! \nu_\tau h^-h^+h^-\pi^0, where h±h^\pm represents a charged pion or kaon. CLEO-II has also observed decays with charged and/or neutral kaons; preliminary results for branching ratios and structure arising from the decay dynamics are given. Connections are made with predictions derived from theoretical models, the Conserved Vector Current theorem, isospin constraints and sum rules.Comment: 9 pages, CALT-68-194

    Observation of the Dsj(2463) and Confirmation of the Dsj*(2317)

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    Using 13.5 inverse-femtobarns of e+e- annihilation data in the CLEO II detector at CESR, we have observed a new narrow state decaying to Ds*+ pio, denoted the DsJ(2463). A possible interpretation holds that this is a J^P = 1+^ partner to the DsJ*(2317) state recently discovered by the BaBar Collaboration which is consistent with J^P = 0^+. We have also confirmed the existence of the DsJ*(2317) in its decay to Ds+ pio. We have measured the masses of both states, accounting for the cross-feed background that the two states represent for each other, and have searched for other decay channels for both states. No narrow resonances are seen in neutral or doubly charged Ds pi modes.Comment: Presented at MRST 2003 conference, "Joefest" Syracuse University, May 13-15, 2003; Conf. on the Intersections of Particle & Nuclear Phyiscs, New York, NY, May 19-24, 2003; Flavor Physics and CP Violation, Ecole Polytechnique, Paris, France, June 3-6, 2003; 7 pages 4 figure

    Mitral annular dynamics are influenced by left ventricular load and contractility in an acute animal model

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    The purpose of this study was to investigate the effects of loading conditions and left ventricular (LV) contractility on mitral annular dynamics. In 10 anesthetized pigs, eight piezoelectric transducers were implanted equidistantly around the mitral annulus. High-fidelity catheters measured left ventricular pressures and the slope of the end-systolic pressure-volume relationship (Ees) determined LV contractility. Adjustments of pre- and afterload were done by constriction of the inferior caval vein and occlusion of the descending aorta. Mitral annulus area indexed to body surface area (MAAi ), annular circularity index (ACI), and nonplanarity angle (NPA) were calculated by computational analysis. MAAi was more dynamic in response to loading interventions than ACI and NPA. However, MAAi maximal cyclical reduction (−Δr) and average deformational velocity (−v) did not change accordingly (p=0.31 and p=0.22). Reduced Ees was associated to attenuation in MAAi -Δr and MAAi -v (r 2=0.744; p=0.001 and r 2=0.467; p=0.029). In conclusion, increased cardiac load and reduced LV contractility may cause deterioration of mitral annular dynamics, likely impairing coaptation and increasing susceptibility to valvular incompetence.publishedVersio

    The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

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    The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

    Experimental search for the decay long-lived neutral kaon going to muonium

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    An experimental study of very rare decays of neutral kaons has been carried out at a new neutral beam line at the Alternating-Gradient Synchrotron at Brookhaven National Laboratory. One focus of this study was a search for the lepton-flavor violating decay K\sbsp{L}{0}\to\mu e. No candidate events indicating occurrence of this process were found. Measurement of the experimental sensitivity was performed by simultaneous observation of the decay K\sbsp{L}{0}\to\pi\sp+\pi\sp-. This yielded a limited at the 90% confidence level on the branching ratio B(K\sbsp{L}{0}\to\mu e) 3˘c\u3c 2.2 ×\times 10\sp{-10}. This limit represents a substantial improvement over previous limits on the rate for this process

    Electrostatic Simulations for the DUNE ND-GAr Field Cage

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    ND-GAr is one of three detector systems in the design of the DUNE Near Detector complex, which will be located on the Fermilab campus, sixty meters underground and 570 m from the source of an intense neutrino beam. ND-GAr will consist of a cylindrical 10-bar gaseous Argon Time Projection Chamber (TPC) and a surrounding sampling electromagnetic calorimeter embedded within a superconducting solenoid, the cryostat and yoke for which together serve as the pressure vessel. While various options for the specific configuration of ND-GAr are being explored, essential design work for the detector has moved forward in recent months. This document describes basic mechanical, electrostatic, and gas flow design features of the ND-GAr TPC and presents results of electrostatic simulations of the interior of the pressure vessel for both single and dual-anode arrangements. Simulations are implemented with the Elmer finite-element software suite and related programs

    Electrostatic Simulations for the DUNE ND-GAr Field Cage

    No full text
    ND-GAr is one of three detector systems in the design of the DUNE Near Detector complex, which will be located on the Fermilab campus, sixty meters underground and 570 m from the source of an intense neutrino beam. ND-GAr will consist of a cylindrical 10-bar gaseous Argon Time Projection Chamber (TPC) and a surrounding sampling electromagnetic calorimeter embedded within a superconducting solenoid, the cryostat and yoke for which together serve as the pressure vessel. While various options for the specific configuration of ND-GAr are being explored, essential design work for the detector has moved forward in recent months. This document describes basic mechanical, electrostatic, and gas flow design features of the ND-GAr TPC and presents results of electrostatic simulations of the interior of the pressure vessel for both single and dual-anode arrangements. Simulations are implemented with the Elmer finite-element software suite and related programs
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