2,010 research outputs found

    Estimates for the Bergman and Szegö projections for pseudoconvex domains of finite type with locally diagonalizable Levi form

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    In this paper, we give precise isotropic and non-isotropic estimates for the Bergman and Szegö projections of a bounded pseudoconvex domain whose boundary points are all of finite type and with locally diagonalizable Levi form. Additional local results on estimates of invariant metrics are also given

    Approximation par des fonctions holomorphes a croissance controleé

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    Let Ω\Omega be a bounded pseuco-convex domain in Cn\Bbb C^n with a \Cal C^{\infty} boundary, and let SS be the set of strictly pseudo-convex points of Ω\partial\Omega. In this paper, we study the asymptotic behaviour of holomorphic functions along normals arising from points of SS. We extend results obtained by M. Ortel and W. Schneider in the unit disc and those of A. Iordan and Y. Dupain in the unit ball of Cn\Bbb C^n. We establish the existence of holomorphic functions of given growth having a "prescribed behaviour" on almost all normals arising from points of SS

    Simulation Application for the LHCb Experiment

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    We describe the LHCb detector simulation application (Gauss) based on the Geant4 toolkit. The application is built using the Gaudi software framework, which is used for all event-processing applications in the LHCb experiment. The existence of an underlying framework allows several common basic services such as persistency, interactivity, as well as detector geometry description or particle data to be shared between simulation, reconstruction and analysis applications. The main benefits of such common services are coherence between different event-processing stages as well as reduced development effort. The interfacing to Geant4 toolkit is realized through a facade (GiGa) which minimizes the coupling to the simulation engine and provides a set of abstract interfaces for configuration and event-by-event communication. The Gauss application is composed of three main blocks, i.e. event generation, detector response simulation and digitization which reflect the different stages performed during the simulation job. We describe the overall design as well as the details of Gauss application with a special emphasis on the configuration and control of the underlying simulation engine. We also briefly mention the validation strategy and the planing for the LHCb experiment simulation.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 6 pages, LaTeX, 9 eps figures. PSN TUMT00

    Study of Inclusive J/psi Production in Two-Photon Collisions at LEP II with the DELPHI Detector

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    Inclusive J/psi production in photon-photon collisions has been observed at LEP II beam energies. A clear signal from the reaction gamma gamma -> J/psi+X is seen. The number of observed N(J/psi -> mu+mu-) events is 36 +/- 7 for an integrated luminosity of 617 pb^{-1}, yielding a cross-section of sigma(J/psi+X) = 45 +/- 9 (stat) +/- 17 (syst) pb. Based on a study of the event shapes of different types of gamma gamma processes in the PYTHIA program, we conclude that (74 +/- 22)% of the observed J/psi events are due to `resolved' photons, the dominant contribution of which is most probably due to the gluon content of the photon.Comment: 13 pages, 8 figures, Accepted by Phys. Lett.

    Search for charginos in e+e- interactions at sqrt(s) = 189 GeV

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    An update of the searches for charginos and gravitinos is presented, based on a data sample corresponding to the 158 pb^{-1} recorded by the DELPHI detector in 1998, at a centre-of-mass energy of 189 GeV. No evidence for a signal was found. The lower mass limits are 4-5 GeV/c^2 higher than those obtained at a centre-of-mass energy of 183 GeV. The (\mu,M_2) MSSM domain excluded by combining the chargino searches with neutralino searches at the Z resonance implies a limit on the mass of the lightest neutralino which, for a heavy sneutrino, is constrained to be above 31.0 GeV/c^2 for tan(beta) \geq 1.Comment: 22 pages, 8 figure

    Study of Tau-pair Production in Photon-Photon Collisions at LEP and Limits on the Anomalous Electromagnetic Moments of the Tau Lepton

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    Tau-pair production in the process e+e- -> e+e-tau+tau- was studied using data collected by the DELPHI experiment at LEP2 during the years 1997 - 2000. The corresponding integrated luminosity is 650 pb^{-1}. The values of the cross-section obtained are found to be in agreement with QED predictions. Limits on the anomalous magnetic and electric dipole moments of the tau lepton are deduced.Comment: 20 pages, 9 figures, Accepted by Eur. Phys. J.

    CP asymmetry in BϕKSB \to \phi K_S in a general two-Higgs-doublet model with fourth-generation quarks

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    We discuss the time-dependent CP asymmetry of decay BϕKSB \to \phi K_S in an extension of the Standard Model with both two Higgs doublets and additional fourth-generation quarks. We show that although the Standard Model with two-Higgs-doublet and the Standard model with fourth generation quarks alone are not likely to largely change the effective sin2β\sin 2 \beta from the decay of BϕKSB \to \phi K_S , the model with both additional Higgs doublet and fourth-generation quarks can easily account for the possible large negative value of sin2β\sin 2 \beta without conflicting with other experimental constraints. In this model, additional large CP violating effects may arise from the flavor changing Yukawa interactions between neutral Higgs bosons and the heavy fourth generation down type quark, which can modify the QCD penguin contributions. With the constraints obtained from bssˉsb \to s \bar{s} s processes such as BXsγB \to X_s \gamma and ΔmBs0\Delta m_{B_s^0}, this model can lead to the effective sin2β\sin 2 \beta to be as large as 0.4- 0.4 in the CP asymmetry of BϕKSB \to \phi K_S.Comment: 13 pages, 5 figures, references added, to appear in Eur.Phys.J.

    Energy dependence of Cronin momentum in saturation model for p+Ap+A and A+AA+A collisions

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    We calculate s\sqrt{s} dependence of Cronin momentum for p+Ap+A and A+AA+A collisions in saturation model. We show that this dependence is consistent with expectation from formula which was obtained using simple dimentional consideration. This can be used to test validity of saturation model (and distinguish among its variants) and measure xx dependence of saturation momentum from experimental data.Comment: LaTeX2e, 12 pages, 8 figure

    Hadronization properties of b quarks compared to light quarks in e+e- -> q qbar from 183 to 200 GeV

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    The DELPHI detector at LEP has collected 54 pb^{-1} of data at a centre-of-mass energy around 183 GeV during 1997, 158 pb^{-1} around 189 GeV during 1998, and 187 pb^{-1} between 192 and 200 GeV during 1999. These data were used to measure the average charged particle multiplicity in e+e- -> b bbar events, _{bb}, and the difference delta_{bl} between _{bb} and the multiplicity, _{ll}, in generic light quark (u,d,s) events: delta_{bl}(183 GeV) = 4.55 +/- 1.31 (stat) +/- 0.73 (syst) delta_{bl}(189 GeV) = 4.43 +/- 0.85 (stat) +/- 0.61 (syst) delta_{bl}(200 GeV) = 3.39 +/- 0.89 (stat) +/- 1.01 (syst). This result is consistent with QCD predictions, while it is inconsistent with calculations assuming that the multiplicity accompanying the decay of a heavy quark is independent of the mass of the quark itself.Comment: 13 pages, 2 figure
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