1,907 research outputs found

    A Feynman graph selection tool in GRACE system

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    We present a Feynman graph selection tool {\tt grcsel}, which is an interpreter written in C language. In the framework of {\tt GRACE}, it enables us to get a subset of Feynman graphs according to given conditions.Comment: 3 pages, 2 figures, Latex, ACAT200

    Suzaku View of Magnetic Cataclysmic Variables

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    Results of magnetic cataclysmic variable studies performed with the Suzaku satellite are reviewed in this article. Particular emphasis is placed on the recent update of X-ray spectral model of intermediate polars, possible kinematically redshifted fluorescent Fe K emission lines, and the magnetic CV contribution to the Galactic ridge X-ray emission

    Anomalous Quartic WWγγWW\gamma\gamma and ZZγγZZ\gamma\gamma Couplings in eγe\gamma Collision With Initial Beams and Final State Polarizations

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    The constraints on the anomalous quartic WWγγWW\gamma\gamma and ZZγγZZ\gamma\gamma gauge boson couplings are investigated through the processes eγWγνee\gamma\to W^{-}\gamma\nu_{e} and eγZγee\gamma\to Z\gamma e. Considering the longitudinal and transverse polarization states of the final W or Z boson and incoming beam polarizations we find 95% confidence level limits on the anomalous coupling parameters a0a_{0} and aca_{c} with an integrated luminosity of 500 fb1fb^{-1} and s\sqrt{s}=0.5, 1 TeV energies. Assuming the W+WγγW^{+}W^{-}\gamma\gamma couplings are independent of the ZZγγZZ\gamma\gamma couplings we show that the longitudinal polarization state of the final gauge boson improves the sensitivity to anomalous couplings by a factor of 2-3 depending on energy and coupling. An extra enhancement in sensitivity by a factor of 1.3 comes from a set of initial beam polarizations

    Observation of an energetic radiation burst from mountain-top thunderclouds

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    During thunderstorms on 2008 September 20, a simultaneous detection of gamma rays and electrons was made at a mountain observatory in Japan located 2770 m above sea level. Both emissions, lasting 90 seconds, were associated with thunderclouds rather than lightning. The photon spectrum, extending to 10 MeV, can be interpreted as consisting of bremsstrahlung gamma rays arriving from a source which is 60 - 130 m in distance at 90% confidence level. The observed electrons are likely to be dominated by a primary population escaping from an acceleration region in the clouds.Comment: 12 pages, 3 figures, accepted for publication in Physical Review Letter
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