16 research outputs found
An improved gamma-ray limit on the density of PBHs
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
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 -
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
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
In-beam tests of the AMS RICH prototype with 20 A GeV/c secondary ions
Abstract A prototype of the AMS Cherenkov imager (RICH) has been tested by means of a low intensity 20 GeV /c per nucleon ion beam coming from the fragmentation of a primary beam of Pb ions. Data have been collected for charges
An improved gamma-ray limit on the density of primordial black holes
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
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