236 research outputs found

    Review of Two-Photon Interactions

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    Presented are recent results of two-photon interactions. Topics inlcude photon structure functions, inclusive hadron production, differential cross sections derived from tagged 2-photon fusion events and results in exclusive hadron production, particularly the observations of the eta_c prime.Comment: 5 pages, Latex, To be published in proceedings to CIPANP held in NY city May 200

    Exploring the Charm Sector with CLEO-c

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    The CLEO collaboration proposes to explore the charm sector starting early 2003. It is foreseen to collect on the order of 6 million D D-bar pairs, 300000 Ds Ds-bar pairs at threshold and one billion J/psi decays. High precision charm data will enable us to validate upcoming Lattice QCD calculations that are expected to produce 1-3% errors for some non-perturbative QCD quantities. These can then be used to improve the accuracy of CKM elements. The radiative J/psi decays will be the first high statistics data set well suited for meson spectroscopy between 1600 and 3000 MeV.Comment: 10 pages, Latex, to be published in proceedings of Hadron 2001 Protvino Added Reference to Detector Section. Corrected typo in table

    Measurement of HQET Parameters and CKM Matrix Elements

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    The determination of CKM matrix elements in the b-sector is discussed, emphasizing the new measurements of Vub and Vcb by the CLEO collaboration.Comment: 4 pages, Latex, to be published in proceedings of Hadron 2001 at Protvin

    When can unlabeled data improve the learning rate?

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    Göpfert C, Ben-David S, Bousquet O, Gelly S, Tolstikhin I, Urner R. When can unlabeled data improve the learning rate? In: Conference on Learning Theory (COLT). 2019

    The Muon Anomalous Magnetic Moment and the Standard Model

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    The muon anomalous magnetic moment measurement, when compared with theory, can be used to test many extensions to the standard model. The most recent measurement made by the Brookhaven E821 Collaboration reduces the uncertainty on the world average of a_mu to 0.7 ppm, comparable in precision to theory. This paper describes the experiment and the current theoretical efforts to establish a correct standard model reference value for the muon anomaly.Comment: Plenary Talk; PANIC'02 XVI Particles and Nuclear International Conference, Osaka, Japan; Sept. 30 - Oct. 4, 2002; Report describes the published 0.7 ppm result and updates the theory statu

    Status Of The FAIR Synchrotron Projects SIS18 And SIS100

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    A large fraction of the program to upgrade the existingheavy ion synchrotron SIS18 as injector for the FAIR synchrotron SIS100 has been successfully completed. With the achieved technical status, a major increase of theaccelerated number of heavy ions could be reached. Thenow available performance especially demonstrates thefeasibility of high intensity beams of medium charge stateheavy ions with a sufficient control of the dynamicvacuum and connected charge exchange loss. Two furtherupgrade measures, the installation of additional magneticalloy (MA) acceleration cavities and the exchange of themain dipole power converter, are presently beingimplemented. For the FAIR synchrotron SIS100, theprocurement of all major components with longproduction times has been started. With the delivery andtesting of several pre-series components, the phase ofoutstanding technical reserach and developments could becompleted and the readiness for series productionachieved

    Search for CP violation in D+→ϕπ+ and D+s→K0Sπ+ decays

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    A search for CP violation in D + → ϕπ + decays is performed using data collected in 2011 by the LHCb experiment corresponding to an integrated luminosity of 1.0 fb−1 at a centre of mass energy of 7 TeV. The CP -violating asymmetry is measured to be (−0.04 ± 0.14 ± 0.14)% for candidates with K − K + mass within 20 MeV/c 2 of the ϕ meson mass. A search for a CP -violating asymmetry that varies across the ϕ mass region of the D + → K − K + π + Dalitz plot is also performed, and no evidence for CP violation is found. In addition, the CP asymmetry in the D+s→K0Sπ+ decay is measured to be (0.61 ± 0.83 ± 0.14)%

    Differential branching fraction and angular analysis of the decay B0→K∗0μ+μ−

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    The angular distribution and differential branching fraction of the decay B 0→ K ∗0 μ + μ − are studied using a data sample, collected by the LHCb experiment in pp collisions at s√=7 TeV, corresponding to an integrated luminosity of 1.0 fb−1. Several angular observables are measured in bins of the dimuon invariant mass squared, q 2. A first measurement of the zero-crossing point of the forward-backward asymmetry of the dimuon system is also presented. The zero-crossing point is measured to be q20=4.9±0.9GeV2/c4 , where the uncertainty is the sum of statistical and systematic uncertainties. The results are consistent with the Standard Model predictions
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