16 research outputs found

    An improved gamma-ray limit on the density of PBHs

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    Gamma-rays are, with antiprotons, a very efficient way to derive upper limits on the density of evaporating black holes. They have been successfully used in the last decades to severely constrain the amount of Primordial Black Holes (PBHs) in our Universe. This article suggests a little refinement, based on the expected background, to improve this limit by a factor of three. The resulting value is : Omega_PBH < 3.3E-9.Comment: To appear in the 28th ICRC conference proceeding

    Atmospheric and Galactic Production and Propagation of Light Antimatter Nuclei

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    The production and propagation of light antimatter nuclei has been calculated using inclusive antiproton production cross sections from a new data analysis, and coalescence models for the production of composite particles. Particles were propagated using recently proven phenomenological approaches. The atmospheric secondary flux is evaluated for the first time. The Galactic flux obtained are larger than those obtained previously in similar calculations. The non-annihilating scattering contributions of the propagated particles are introduced. The preliminary results are shown and discussed.Comment: 4 pages, Contribution to the ICRC 200

    The AMS-02 RICH Imager Prototype - In-Beam Tests with 20 GeV/c per Nucleon Ions -

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    A prototype of the AMS Cherenkov imager (RICH) has been tested at CERN by means of a low intensity 20 GeV/c per nucleon ion beam obtained by fragmentation of a primary beam of Pb ions. Data have been collected with a single beam setting, over the range of nuclear charges 2<Z<~45 in various beam conditions and using different radiators. The charge Z and velocity beta resolutions have been measured.Comment: 4 pages, contribution to the ICRC 200

    Very high frequency gravitational wave background in the universe

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    Astrophysical sources of high frequency gravitational radiation are considered in association with a new interest to very sensitive HFGW receivers required for the laboratory GW Hertz experiment. A special attention is paid to the phenomenon of primordial black holes evaporation. They act like black body to all kinds of radiation, including gravitons, and, therefore, emit an equilibrium spectrum of gravitons during its evaporation. Limit on the density of high frequency gravitons in the Universe is obtained, and possibilities of their detection are briefly discussed.Comment: 14 page

    An improved gamma-ray limit on the density of primordial black holes

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    Gamma-rays are, with antiprotons, a very efficient way to derive upper limits on the density of evaporating black holes. They have been successfully used in the last decades to severely constrain the amount of Primordial Black Holes (PBHs) in our Universe. This article suggests a little refinement, based on the expected background, to improve this limit by a factor of three. The resulting value is : Omega_PBH < 3.3E-9

    Flux of light antimatter nuclei near Earth, induced by cosmic rays in the Galaxy and in the atmosphere

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    The fluxes of light antinuclei A<=4 induced near earth by Cosmic Ray intera ctions with the interstellar matter in the Galaxy and with the Earth atmosphere, are calculated in a phenomenological framework. The hadronic production cross section for antinucleons is based on a recent parametrization of a wide set of accelerator data. The production of light nuclei is calculated using coalescence models. For the standard coalescence model, the coalescence radius is fitted to the available experimental data. The non annihilating inelastic scattering process for the antideuterons is discussed and taken into account for the first time via a more realistic procedure than used so far for antiprotons
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