800 research outputs found

    Architecture of a Silicon Strip Beam Position Monitor

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    A collaboration between Fermilab and the Institute for High Energy Physics (IHEP), Beijing, has developed a beam position monitor for the IHEP test beam facility. This telescope is based on 5 stations of silicon strip detectors having a pitch of 60 microns. The total active area of each layer of the detector is about 12x10 cm2. Readout of the strips is provided through the use of VA1` ASICs mounted on custom hybrid printed circuit boards and interfaced to Adapter Cards via copper-over-kapton flexible circuits. The Adapter Cards amplify and level-shift the signal for input to the Fermilab CAPTAN data acquisition nodes for data readout and channel configuration. These nodes deliver readout and temperature data from triggered events to an analysis computer over gigabit Ethernet links.Comment: Submitted to TWEPP 201

    Photon Cross Sections at Ecm = 2 TeV

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    Photon production rates have been studied by the D0 and CDF experiments in Run II of the Fermilab Tevatron Collider. Measurements of the inclusive isolated photon cross section and the di-photon cross section are presented, based on integrated luminosities of 0.3 fb-1 and 0.2 fb-1, respectively. The results are compared to perturbative QCD calculations in various approximations.Comment: 4 pages 2 figures, presented at XLIrst Rencontres de Moriond on ``QCD and High Energy Hadronic Interactions'', La Thuile, Italy, March 18-25, 2006, on behalf of the CDF and D0 collaboration

    Towards a precise measurement of the top quark Yukawa coupling at the ILC

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    A precise measurement of the top quark Yukawa coupling is of great importance, since it may shed light on the mechanism of EWSB. We study the prospects of such measurement during the first phase of the ILC at sqrt(s)=500 GeV, focusing in particular on recent theoretical developments as well as the potential benefits of beam polarization. It is shown that both yield improvements that could possibly lead to a measurement competitive with the LHC.Comment: Invited talk at 2005 International Linear Collider Physics and Detector Workshop and Second ILC Accelerator Workshop, Snowmass, CO (Snowmass05) 3 pages, LaTeX, 3 eps figure

    Searches for New Physics in Top Events at the Tevatron

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    Recent results of searches for new physics in top events at the Tevatron are presented. In case of CDF three searches are discussed using 6.0 to 8.7 fb^{-1} of data, with the latter being the final CDF data sample available for this kind of analysis. CDF carried out a search for Top + jet resonance production, dark matter production in association with single top and boosted tops. No signs of new physics are observed and instead upper limits are derived. D{\O} used 5.3 fb^{-1} of data and searched for a narrow resonance in ttbar production and a time dependent ttbar cross section, which would reveal a violation of Lorentz invariance. However, no signs for deviations from Standard Model are seen and instead upper limits for non-Standard Model contributions are calculated.Comment: 4 pages, 7 figures, To appear in Proceedings of Moriond QCD 201

    Bs, Bc and b-baryons

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    We present the latest measurements on masses, lifetimes and branching fractions for the B_s and B_c mesons as well as for b-baryons. For the B_s meson we discuss as well the latest results on mixing. These results were produced by the CDF and D0 experiments at Fermilab or by earlier LEP and PEPII experiments.Comment: 13 pages, 17 figures, contribution to the Proceedings of the 25th International Symposium on Physics in Collision (PIC 05), Prague, Czech Republic, July 6-9, 2005 (In version 2 there were a couple of typos fixed and a reference added in section 2

    Status of the LBNE Neutrino Beamline

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    The Long Baseline Neutrino Experiment (LBNE) will utilize a neutrino beamline facility located at Fermilab to carry out a compelling research program in neutrino physics. The facility will aim a beam of neutrinos toward a detector placed at the Homestake Mine in South Dakota. The neutrinos are produced in a three-step process. First, protons from the Main Injector (60-120 GeV) hit a solid target and produce mesons. Then, the charged mesons are focused by a set of focusing horns into the decay pipe, towards the far detector. Finally, the mesons that enter the decay pipe decay into neutrinos. The parameters of the facility were determined taking into account several factors including the physics goals, the Monte Carlo modeling of the facility, spacial and radiological constraints and the experience gained by operating the NuMI facility at Fermilab. The initial beam power is expected to be ~700 kW, however some of the parameters were chosen to be able to deal with a beam power of 2.3 MW. We discuss here the status of the conceptual design and the associated challenges.Comment: 6 pages, 3 figure

    Physics at a New Fermilab Proton Driver

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    In 2004, motivated by the recent exciting developments in neutrino physics, the Fermilab Long Range Planning Committee identified a new high intensity Proton Driver as an attractive option for the future. At the end of 2004 the APS ``Study on the Physics of Neutrinos'' concluded that the future U.S. neutrino program should have, as one of its components, ``A proton driver in the megawatt class or above and neutrino superbeam with an appropriate very large detector capable of observing CP violation and measuring the neutrino mass-squared differences and mixing parameters with high precision''. The presently proposed Fermilab Proton Driver is designed to accomplish these goals, and is based on, and would help develop, Linear Collider technology. In this paper the Proton Driver parameters are summarized, and the potential physics program is described.Comment: 12 pages, 4 figures. Presented at the III International Workshop on Neutrino Oscillations in Venice, February 7-10, 200

    Top Quark Current Experimental Status

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    Ten years after its discovery at the Tevatron collider, we still know little about the top quark. Its large mass suggests it may play a key role in the mechanism of Electroweak Symmetry Breaking (EWSB), or open a window of sensitivity to new physics related to EWSB and preferentially coupled to it. To determine whether this is the case, precision measurements of top quark properties are necessary. The high statistics samples being collected by the Tevatron experiments during Run II start to incisively probe the top quark sector. This report summarizes the experimental status of the top quark, focusing in particular on the recent measurements from the Tevatron.Comment: 12 pages, 6 figures, 1 table. Talk presented at TOP 2006, International Workshop on Top Quark Physics, Coimbra, Portugal, January 12-15, 2006. To appear in the proceeding

    Construction of AC Motor Controllers for NOvA Experiment Upgrades

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    I have been constructing Alternating Current (AC) motor controllers for manipulation of particle beam detectors. The capability and reliability of these motor controllers are essential to the Laboratory's mission of accurate analysis of the particle beam's position. The device is moved in and out of the beam's path by the motor controller followed by the Neutrinos at the Main Injector Off-Axis {\nu}e Appearance (NOvA) Experiment further down the beam pipe. In total, I built and tested ten ac motor controllers for new beam operations in the NOvA experiment. These units will prove to be durable and provide extremely accurate beam placement for NO{\nu}A Experiment far into the future.Comment: 11 p

    Recycler barrier RF buckets

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    The Recycler Ring at Fermilab uses a barrier rf system for all of its rf manipulations. In this paper, I will give an overview of historical perspective on barrier rf systems, the longitudinal beam dynamics issues, aspects of rf linearization to produce long flat bunches and methods used for emittance measurements of the beam in the RR barrier rf buckets. Current rf manipulation schemes used for antiproton beam stacking and longitudinal momentum mining of the RR beam for the Tevatron collider operation are explained along with their importance in spectacular success of the Tevatron luminosity performance.Comment: 30 pp. Submitted as a chapter in a book on the Tevatron edited by Valeri Lebedev and Vladimir Shiltse
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