67 research outputs found

    A description of drift chambers used in a Fermilab experiment

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    We give a detailed description of the drift chamber system used in a charm search at Fermilab. All important aspects of design and performance are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/21645/1/0000029.pd

    A search for new particles in proton‐nucleus collisions at 400 GeV/c

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    We report preliminary results from a search for new particles produced in proton‐nucleus collisions at 400 GeV/c. A double‐arm spectrometer is used to detect two‐body final states where each spectrometer arm has the capability of uniquely identifying Π±, K±, p, ?, μ±, and ϕ. The Jψ is measured in the μ+μ− mode.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87398/2/30_1.pd

    High energy hadrons in EAS at mountain altitude

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    An extensive simulation has been carried out to estimate the physical interpretation of dynamical factors such as , in terms of high energy interaction features, concentrated in the present analysis on the average transverse momentum. It appears that the large enhancement observed for versus primary energy, suggesting in earliest analysis a significant rise of with energy, is only the result of the limited resolution of the detectors and remains in agreement with a wide range of models used in simulations.Comment: 13 pages, 6 PostScript figures, LaTeX Subm. to JPhys

    Design and Test of a Forward Neutron Calorimeter for the ZEUS Experiment

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    A lead scintillator sandwich sampling calorimeter has been installed in the HERA tunnel 105.6 m from the central ZEUS detector in the proton beam direction. It is designed to measure the energy and scattering angle of neutrons produced in charge exchange ep collisions. Before installation the calorimeter was tested and calibrated in the H6 beam at CERN where 120 GeV electrons, muons, pions and protons were made incident on the calorimeter. In addition, the spectrum of fast neutrons from charge exchange proton-lucite collisions was measured. The design and construction of the calorimeter is described, and the results of the CERN test reported. Special attention is paid to the measurement of shower position, shower width, and the separation of electromagnetic showers from hadronic showers. The overall energy scale as determined from the energy spectrum of charge exchange neutrons is compared to that obtained from direct beam hadrons.Comment: 45 pages, 22 Encapsulated Postscript figures, submitted to Nuclear Instruments and Method

    Fluorocarbon evaporative cooling developments for the ATLAS pixel and semiconductor tracking detectors

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    Heat transfer coefficients 2-5.103 Wm-2K-1 have been measured in a 3.6 mm I.D. heated tube dissipating 100 Watts - close to the full equivalent power (~110 W) of a barrel SCT detector "stave" - over a range of power dissipations and mass flows in the above fluids. Aspects of full-scale evaporative cooling circulator design for the ATLAS experiment are discussed, together with plans for future development

    Complete Next to Leading Order QCD Corrections to the Photon Structure Functions F2γ(x,Q2)F^\gamma_2(x,Q^2) and FLγ(x,Q2)F_L^\gamma(x,Q^2)

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    We present the complete NLO QCD analysis of the photon structure functions F2γ(x,Q2)F_2^\gamma(x,Q^2) and FLγ(x,Q2)F_L^\gamma(x,Q^2) for a real photon target. In particular we study the heavy flavor content of the structure functions which is due to two different production mechanisms, namely collisions of a virtual photon with a real photon, and with a parton. We observe that the charm contributions are noticeable for F2γ(x,Q2)F_2^\gamma(x,Q^2) as well as FLγ(x,Q2)F_L^\gamma(x,Q^2) in the x-region studied.Comment: Latex 34 pages, 24 figures, uuencoded, attached at end, ITP-SB-93-46, FERMILAB-Pub-93/240-T, SMU HEP 93-1

    New limits on D0 (1.865) production in proton-nucleus collisions at 400 GeV/c

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    We present final results of a sensitive search for new particles in [pi]+/-K[mnplus] effective mass spectra observed in proton-nucleus collisions at 400 GeV/c. We establish a limit for D0 (1.865) production B[pi]+[pi]- d[sigma]/dy ycm[approximate] -0.4. For D0 --> [pi]-K+ the limit is 290 nb/nucleon.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22811/1/0000369.pd

    Threshold Effects on Heavy Quark Production in γγ\gamma\gamma Interactions

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    The exchange of gluons between heavy quarks produced in e+ee^+e^- interactions results in an enhancement of their production near threshold. We study QCD threshold effects in γγ\gamma\gamma collisions. The results are relevant to heavy quark production by beamstrahlung and laser back-scattering in future linear collider experiments. Detailed predictions for top, bottom and charm production are presented.Comment: 26 pages, 12 figures available in ps upon request, revtex, MAD/PH/701 (revised version

    Search for high-mass narrow resonances in virtual photon-photon interactions

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