583 research outputs found

    The 1953 Cosmic Ray Conference at Bagneres de Bigorre

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    The cosmic ray conference at Bagn`eres de Bigorre in July, 1953 organized by Patrick Blackett and Louis Leprince-Ringuet was a seminal one. It marked the beginning of sub atomic physics and its shift from cosmic ray research to research at the new high energy accelerators. The knowledge of the heavy unstable particles found in the cosmic rays was essentially correct in fact and interpretation and defined the experiments that needed to be carried out with the new accelerators. A large fraction of the physicists who had been using cosmic rays for their research moved to the accelerators. This conference can be placed in importance in the same category as two other famous conferences, the Solvay congress of 1927 and the Shelter Island Conference of 1948

    A Nonsingular Two Dimensional Black Hole

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    We construct a model of gravity in 1+1 spacetime dimensions in which the solutions approach the Schwarzschild metric at large rr and de Sitter space far inside the horizon. Our model may be viewed as a two dimensional application of the `Limiting Curvature Construction' recently proposed by two of the authors.Comment: 9 pages, 1 figure (available from the authors), uses LATEX, Brown preprint BROWN-HET-907, May 199

    Scalar wave propagation in topological black hole backgrounds

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    We consider the evolution of a scalar field coupled to curvature in topological black hole spacetimes. We solve numerically the scalar wave equation with different curvature-coupling constant Îľ\xi and show that a rich spectrum of wave propagation is revealed when Îľ\xi is introduced. Relations between quasinormal modes and the size of different topological black holes have also been investigated.Comment: 26 pages, 18 figure

    General Static Solutions of 2-dimensional Einstein-Dilaton-Maxwell-Scalar Theories

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    General static solutions of effectively 2-dimensional Einstein-Dilaton-Maxwell-Scalar theories are obtained. Our model action includes a class of 2-d dilaton gravity theories coupled with a U(1)U(1) gauge field and a massless scalar field. Therefore it also describes the spherically symmetric reduction of dd-dimensional Einstein-Scalar-Maxwell theories. The properties of the analytic solutions are briefly discussed.Comment: 16 pages, Latex fil

    Interior Structure of a Charged Spinning Black Hole in (2+1)(2+1)-Dimensions

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    The phenomenon of mass inflation is shown to occur for a rotating black hole. We demonstrate this feature in (2+1)(2+1) dimensions by extending the charged spinning BTZ black hole to Vaidya form. We find that the mass function diverges in a manner quantitatively similar to its static counterparts in (3+1)(3+1), (2+1)(2+1) and (1+1)(1+1) dimensions.Comment: 5 pages, 2 figures (appended as postscript files), WATPHYS-TH94/0

    Photon Statistics; Nonlinear Spectroscopy of Single Quantum Systems

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    A unified description of multitime correlation functions, nonlinear response functions, and quantum measurements is developed using a common generating function which allows a direct comparison of their information content. A general formal expression for photon counting statistics from single quantum objects is derived in terms of Liouville space correlation functions of the material system by making a single assumption that spontaneous emission is described by a master equation

    Quantum Interference: From Kaons to Neutrinos (with Quantum Beats in between)

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    Using the vehicle of resolving an apparent paradox, a discussion of quantum interference is presented. The understanding of a number of different physical phenomena can be unified, in this context. These range from the neutral kaon system to massive neutrinos, not to mention quantum beats, Rydberg wave packets, and neutron gravity.Comment: 12 pages, LaTeX, 3 figure

    Challenges and Obstacles for a Bouncing Universe in Brane Models

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    A Brane evolving in the background of a charged AdS black-hole displays in general a bouncing behaviour with a smooth transition from a contracting to an expanding phase. We examine in detail the conditions and consequences of this behaviour in various cases. For a cosmological-constant-dominated Brane, we obtain a singularity-free, inflationary era which is shown to be compatible only with an intermediate-scale fundamental Planck mass. For a radiation-dominated Brane, the bouncing behaviour can occur only for background-charge values exceeding those allowed for non-extremal black holes. For a matter-dominated Brane, the black-hole mass affects the proper volume or the expansion rate of the Brane. We also consider the Brane evolving in an asymmetric background of two distinct charged AdS black hole spacetimes being bounded by the Brane and find that, in the case of an empty critical Brane, bouncing behaviour occurs only if the black-hole mass difference is smaller than a certain value. The effects of a Brane curvature term on the bounce at early and late times are also investigated.Comment: 23 pages, Latex file, comments and references added, version to appear in Phys. Rev.

    Quantum algebra in the mixed light pseudoscalar meson states

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    In this paper, we investigate the entanglement degrees of pseudoscalar meson states via quantum algebra Y(su(3)). By making use of transition effect of generators J of Y(su(3)), we construct various transition operators in terms of J of Y(su(3)), and act them on eta-pion-eta mixing meson state. The entanglement degrees of both the initial state and final state are calculated with the help of entropy theory. The diagrams of entanglement degrees are presented. Our result shows that a state with desired entanglement degree can be achieved by acting proper chosen transition operator on an initial state. This sheds new light on the connect among quantum information, particle physics and Yangian algebra.Comment: 9 pages, 3 figure

    Search for the Proton Decay Mode proton to neutrino K+ in Soudan 2

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    We have searched for the proton decay mode proton to neutrino K+ using the one-kiloton Soudan 2 high resolution calorimeter. Contained events obtained from a 3.56 kiloton-year fiducial exposure through June 1997 are examined for occurrence of a visible K+ track which decays at rest into mu+ nu or pi+ pi0. We found one candidate event consistent with background, yielding a limit, tau/B > 4.3 10^{31} years at 90% CL with no background subtraction.Comment: 13 pages, Latex, 3 tables and 3 figures, Accepted by Physics Letters
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