1,047 research outputs found

    CKM Matrix: Status and New Developments

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    An analysis of the CKM matrix parameters within the {\it R}fit approach is presented using updated input values with special emphasis on the recent sin2β\sin{2\beta} measurements from BABAR and Belle. The QCD Factorisation Approach describing Bππ,KπB \to \pi\pi,K\pi decays has been implemented in the software package CKMfitter. Fits using branching ratios and CP asymmetries are discussed.Comment: 5 pages, 6 postscript figures, contribution to the proceedings of the 9th International Symposium on Heavy Flavour Physics, September 2001, Pasadena, US

    Zoom sur la violation de CP à l'occasion des résultats obtenus par les expériences BABAR et BELLE

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    En août dernier, les expériences BABAR et Belle ont annoncé presque simultanément la découverte d'une « différence spectaculaire entre matière et antimatière ». Cette information a été immédiatement relayée sous forme de communiqués de presse avant d'être présentée à la Conférence Internationale de Physique des Hautes Energies (ICHEP 2004) à Pékin deux semaines plus tard

    CP Violation

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    Introductory lecture to CP violation in the Standard Model

    Concepts for Baryogenesis

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    The lecture introduces three common scenarios for baryogenesis: (i) GUT-type baryogenesis in the early universe, (ii) baryogenesis through electroweak phase transitions, and (iii) baryogenesis through leptogenesis. Prerequisites to this, such as antimatter, matter-antimatter asymmetry, dynamics of the universe, equilibrium thermodynamics, the Higgs mechanism, and the CKM matrix are briefly recalled prior to the baryogenesis discussion

    Discovery Physics at the LHC

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    Introductory lecture to physics beyond the Standard Model searches at the LHC. The first half of the lecture is devoted to the phenomenological motivation of the most prominent new physics scenarios, and the second half deals with their experimental signatures

    Discovery Physics at the LHC

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    Introductory lecture to the phenomenology of, and the LHC search for physics beyond the Standard Model (BSM). The first lecture discusses the empirical and theoretical reasons that require BSM physics, and how Supersymmetry, extra dimension and little Higgs models can cope with these. The second lecture introduces the experimental approaches adopted by ATLAS and CMS to search for BSM physics signals, and to measure some of their properties

    Three-dimensional track reconstruction for directional Dark Matter detection

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    Directional detection of Dark Matter is a promising search strategy. However, to perform such detection, a given set of parameters has to be retrieved from the recoiling tracks : direction, sense and position in the detector volume. In order to optimize the track reconstruction and to fully exploit the data of forthcoming directional detectors, we present a likelihood method dedicated to 3D track reconstruction. This new analysis method is applied to the MIMAC detector. It requires a full simulation of track measurements in order to compare real tracks to simulated ones. We conclude that a good spatial resolution can be achieved, i.e. sub-mm in the anode plane and cm along the drift axis. This opens the possibility to perform a fiducialization of directional detectors. The angular resolution is shown to range between 20^\circ to 80^\circ, depending on the recoil energy, which is however enough to achieve a high significance discovery of Dark Matter. On the contrary, we show that sense recognition capability of directional detectors depends strongly on the recoil energy and the drift distance, with small efficiency values (50%-70%). We suggest not to consider this information either for exclusion or discovery of Dark Matter for recoils below 100 keV and then to focus on axial directional data.Comment: 27 pages, 20 figure

    Rational approximations in Analytic QCD

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    We consider the ``modified Minimal Analytic'' (mMA) coupling that involves an infrared cut to the standard MA coupling. The mMA coupling is a Stieltjes function and, as a consequence, the paradiagonal Pade approximants converge to the coupling in the entire Q2Q^2-plane except on the time-like semiaxis below the cut. The equivalence between the narrow width approximation of the discontinuity function of the coupling, on the one hand, and this Pade (rational) approximation of the coupling, on the other hand, is shown. We approximate the analytic analogs of the higher powers of mMA coupling by rational functions in such a way that the singularity region is respected by the approximants.Several comparisons, for real and complex arguments Q2Q^2, between the exact and approximate expressions are made and the speed of convergence is discussed. Motivated by the success of these approximants, an improvement of the mMA coupling is suggested, and possible uses in the reproduction of experimental data are discussed.Comment: 12 pages,9 figures (6 double figures); figs.6-8 corrected due to a programming error; analysis extended to two IR cutoffs; Introduction rewritten; to appear in J.Phys.

    Prospects for the Measurement of the Higgs Yukawa Couplings to b and c quarks, and muons at CLIC

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    The investigation of the properties of the Higgs boson, especially a test of the predicted linear dependence of the branching ratios on the mass of the final state is going to be an integral part of the physics program at colliders at the energy frontier for the foreseeable future. The large Higgs boson production cross section at a 3TeV CLIC machine allows for a precision measurement of the Higgs branching ratios. The cross section times branching ratio of the decays H->bb, H->cc and H->{\mu}{\mu} of a Standard Model Higgs boson with a mass of 120 GeV can be measured with a statistical uncertainty of 0.23%, 3.1% and 15%, respectively, assuming an integrated luminosity of 2 ab-1.Comment: 6 pages, 4 figure
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