6,630 research outputs found

    Object oriented data analysis in ALEPH

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    This article describes the status of the ALPHA^{++} project of the ALEPH collaboration. The ALEPH data have been converted from Fortran data structures (BOS banks) into C^{++} objects and stored in a object oriented database (Objectivity/DB), using tools provided by the RD45 collaboration and the LHC^{++} software project at CERN. A description of the database setup and of a preliminary version of an object oriented analysis program is given.This article describes the status of the ALPHA^{++} project of the ALEPH collaboration. The ALEPH data have been converted from Fortran data structures (BOS banks) into C^{++} objects and stored in a object oriented database (Objectivity/DB), using tools provided by the RD45 collaboration and the LHC^{++} software project at CERN. A description of the database setup and of a preliminary version of an object oriented analysis program is given

    Higgs mediated Double Flavor Violating top decays in Effective Theories

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    The possibility of detecting double flavor violating top quark transitions at future colliders is explored in a model-independent manner using the effective Lagrangian approach through the t→uiτμt \to u_i\tau \mu (ui=u,cu_i=u,c) decays. A Yukawa sector that contemplates SUL(2)×UY(1)SU_L(2)\times U_Y(1) invariants of up to dimension six is proposed and used to derive the most general flavor violating and CP violating qiqjHq_iq_jH and liljHl_il_jH vertices of renormalizable type. Low-energy data, on high precision measurements, and experimental limits are used to constraint the tuiHtu_iH and HτμH\tau \mu vertices and then used to predict the branching ratios for the t→uiτμt \to u_i\tau \mu decays. It is found that this branching ratios may be of the order of 10−4−10−5 10^{-4}-10^{-5}, for a relative light Higgs boson with mass lower than 2mW2m_W, which could be more important than those typical values found in theories beyond the standard model for the rare top quark decays t→uiViVjt\to u_iV_iV_j (Vi=W,Z,γ,gV_i=W,Z,\gamma, g) or t→uil+l−t\to u_il^+l^-. %% LHC experiments, by using a total integrated luminosity of 3000fb−1\rm 3000 fb^{-1} of data, will be able to rule out, at 95% C.L., DFV top quark decays up to a Higgs mass of 155 GeV/c2c^2 or discover such a process up to a Higgs mass of 147 GeV/c2c^2.Comment: 24 pages, 11 figure

    Beam test calibration of the balloon-borne imaging calorimeter for the CREAM experiment

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    CREAM (Cosmic Ray Energetics And Mass) is a multi-flight balloon mission designed to collect direct data on the elemental composition and individual energy spectra of cosmic rays. Two instrument suites have been built to be flown alternately on a yearly base. The tungsten/Sci-Fi imaging calorimeter for the second flight, scheduled for December 2005, was calibrated with electron and proton beams at CERN. A calibration procedure based on the study of the longitudinal shower profile is described and preliminary results of the beam test are presented.Comment: 4 pages, 4 figures. To be published in the Proceedings of 29th International Cosmic Ray Conference (ICRC 2005), Pune, India, August 3-10, 200

    Measurements of cosmic-ray energy spectra with the 2nd CREAM flight

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    During its second Antarctic flight, the CREAM (Cosmic Ray Energetics And Mass) balloon experiment collected data for 28 days, measuring the charge and the energy of cosmic rays (CR) with a redundant system of particle identification and an imaging thin ionization calorimeter. Preliminary direct measurements of the absolute intensities of individual CR nuclei are reported in the elemental range from carbon to iron at very high energy.Comment: 4 pages, 3 figures, presented at XV International Symposium on Very High Energy Cosmic Ray Interactions (ISVHECRI 2008

    Elemental energy spectra of cosmic rays measured by CREAM-II

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    We present new measurements of the energy spectra of cosmic-ray (CR) nuclei from the second flight of the balloon-borne experiment CREAM (Cosmic Ray Energetics And Mass). The instrument (CREAM-II) was comprised of detectors based on different techniques (Cherenkov light, specific ionization in scintillators and silicon sensors) to provide a redundant charge identification and a thin ionization calorimeter capable of measuring the energy of cosmic rays up to several hundreds of TeV. The data analysis is described and the individual energy spectra of C, O, Ne, Mg, Si and Fe are reported up to ~ 10^14 eV. The spectral shape looks nearly the same for all the primary elements and can be expressed as a power law in energy E^{-2.66+/-0.04}. The nitrogen absolute intensity in the energy range 100-800 GeV/n is also measured.Comment: 4 pages, 3 figures, presented at ICRC 2009, Lodz, Polan

    An overview of the design, construction and performance of large area triple-GEM prototypes for future upgrades of the CMS forward muon system

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    GEM detectors are used in high energy physics experiments given their good spatial resolution, high rate capability and radiation hardness. An international collaboration is investigating the possibility of covering the 1.6 < vertical bar eta vertical bar < 2.4 region of the CMS muon endcaps with large-area triple-GEM detectors. The CMS high-eta area is actually not fully instrumented, only Cathode Strip Chamber (CSC) are installed. The vacant area presents an opportunity for a detector technology able to to cope with the harsh radiation environment; these micropattern gas detectors are an appealing option to simultaneously enhance muon tracking and triggering capabilities in a future upgrade of the CMS detector. A general overview of this feasibility study is presented. Design and construction of small (10cm x 10cm) and full-size trapezoidal (1m x 0.5m) triple-GEM prototypes is described. Results from measurements with x-rays and from test beam campaigns at the CERN SPS is shown for the small and large prototypes. Preliminary simulation studies on the expected muon reconstruction and trigger performances of this proposed upgraded muon system are reported
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