227 research outputs found

    Generalized Parton Distributions, Deeply Virtual Compton Scattering and TMDs

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    Parton distributions in impact parameter space, which are obtained by Fourier transforming GPDs, exhibit a significant deviation from axial symmetry when target and/or quark are transversely polarized. In combination with the final state interactions, this transverse deformation provides a natural mechanism for naive-T odd transverse single-spin asymmetries in semi-inclusive DIS. The deformation of PDFs in impact parameter space can also be related to the transverse force acting on the active quark in polarized DIS at higher twist.Comment: 4 pages, invited talk at CIPANP0

    Cosmic Ray Muons Timing in the ATLAS Detector

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    In this talk I discuss the use of calorimeter timing both for detector commissioning and in searches for new physics. In particular I present real and simulated cosmic ray muons data results for the ATLAS Tile Calorimeter system. The analysis shows that several detector errors such as imperfect calibrations can be uncovered. I also demonstrate the use of ATLAS Tile Calorimeters excellent timing resolution in suppressing cosmic ray fake missing transverse energy in searches for supersymmetry.Comment: Proceedings of CIPANP 2009, peer-reviewed by the ATLAS Collaboratio

    The fate of the Mach cone in covariant transport theory

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    An intriguing potential signature of hydrodynamic behavior in relativistic A+A reactions at Relativistic Heavy Ion Collider (RHIC) energies is conical flow induced by fast supersonic particles traversing the hot and dense medium. Here I present first results on the evolution of Mach shocks in 2->2 covariant transport theory, in a static uniform medium.Comment: Presentation at CIPANP 2009 (Tenth Conference on the Intersections of Particle and Nuclear Physics), May 26-31, 2009, Torrey Pines, California, US

    Physics Beyond the Standard Model

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    I present a brief overview of some exciting possibilities for physics Beyond the Standard Model. I include short discussions of neutrino physics, the strong CP problem and axions, GUTs, large and warped extra dimensions, Little Higgs models and supersymmetry. The chances appear excellent that in the next few years-- as the LHC era gets underway-- data from a bevy of experiments will point the way to a new paradigm for the laws of physics as we know them.Comment: 6 pages; to appear in the Proceedings of the Tenth Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2009), San Diego, California, 26-31 May, 200

    IceCube: Neutrinos Associated with Cosmic Rays

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    After a brief review of the status of the kilometer-scale neutrino observatory IceCube, we discuss the prospect that such detectors discover the still-enigmatic sources of cosmic rays. After all, this aspiration set the scale of the instrument. While only a smoking gun is missing for the case that the Galactic component of the cosmic-ray spectrum originates in supernova remnants, the origin of the extragalactic component remains as inscrutable as ever. We speculate on the role of the nearby active galaxies Centaurus A and M87.Comment: 9 pages, 6 .pdf figures, from a paper presented at CIPANP 09, Torrey Pines, San Diego, C

    alpha_s From the Lattice and Hadronic Tau Decays

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    Until recently, determinations of alpha_s(M_Z) from hadronic tau decays and the analysis of short-distance-sensitive lattice observables yielded results which, though precise, were not in good agreement. I review new analyses that bring these into good agreement and provide some details on the source of the main changes in the tau decay analysis.Comment: 4 pages, prepared for the proceedings of CIPANP 09, San Diego, USA, March 26-31, 200

    Charm Input for Determining gamma/phi_3

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    Overconstraining the CKM unitarity triangle with precision measurements of its angles continues to test the validity of the Standard Model. One of these angles, gamma/phi_3, has been measured by studying B+- -> D K+- decays, where D = D0 or D0-bar. I present recent results of hadronic D decays which will improve the sensitivity of gamma/phi_3 measurements.Comment: 4 pages, CIPANP 2009 proceedings; references adde

    Photon+jets measurements at D0

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    In this paper, we present a few measurements done at the D0 experiment at the Fermilab Tevatron Collider. These measurements include the triple differential cross sections of the photon and associated jet production, the photon and heavy flavour (b and c) jet, and finally, study of the event with double parton scattering using photon+3 jets events. Each section below presents a brief description of those measurements and results.Comment: To be published in the proceedings of DPF-2009, Detroit, MI, July 2009, eConf C09072

    Hadronic and Spin Physics: Review

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    I will summarize the numerous contributions which were presented in the session, Hadronic and Spin Physics, largely dominated by new experimental results.Comment: 9 pages, 4 figures, Invited talk presented at CIPANP 2009, San Diego, California, USA, May 26-31 2009, To appear in the AIP Conference Proceeding

    Photon-jet coincidence measurements in polarized pp collisions at sqrt{s}=200 GeV with the STAR Endcap Calorimeter

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    Recent inclusive measurements with polarized proton-proton collisions at RHIC provide significant constraints on the polarized gluon distribution, Delta g(x), integrated over the gluon momentum range 0.02 < x < 0.3. Di-jet and photon-jet coincidence measurements will allow to study the x-dependence of Delta g(x). In this report we present the status of photon-jet coincidence studies for photons detected at forward pseudorapidity, 1.08<eta<2, using the STAR Endcap Calorimeter.Comment: Talk given at the Tenth Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2009), 26-31 May 2009, San Diego CA, USA; 4 pages, 3 figure
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