English
Related papers

Related papers: Cosmic-Ray Positrons: Are There Primary Sources?

200 papers

In this paper we note that the spectral intensities of antiprotons observed in Galactic cosmic rays in the energy range ~ 1-100 GeV by BESS, PAMELA and AMS instruments display nearly the same spectral shape as that generated by primary…

High Energy Astrophysical Phenomena · Physics 2016-08-24 Ramanath Cowsik , Tsitsi Madziwa-Nussinov

A new generation of upcoming space-based experiments will soon start to probe the spectrum of cosmic ray antiparticles with an unprecedented accuracy and, in particular, will open up a window to energies much higher than those accessible so…

Astrophysics · Physics 2008-11-26 Torsten Bringmann , Pierre Salati

Cosmic rays are a sample of solar, galactic and extragalactic matter. Their origin and properties are one of the most intriguing question in modern astrophysics. The most energetic events and active objects in the Universe: supernovae…

High Energy Astrophysical Phenomena · Physics 2012-08-30 Piergiorgio Picozza , Mirko Boezio

The center of the our Galaxy is a region where very energetic phenomena take place. In particular powerful cosmic ray sources can be located in that region. The cosmic rays accelerated in these sources may interact with ambient protons…

High Energy Astrophysical Phenomena · Physics 2015-06-18 A. D. Supanitsky

The antiparticle energy spectra of Galactic cosmic rays (CRs) have several exciting features such as the unexpected positron excess at $E\sim$10-200\,GeV and the remarkably hard antiproton flux at $E\sim$\,60--450\,GeV recently measured by…

High Energy Astrophysical Phenomena · Physics 2018-07-31 Jie Feng , Nicola Tomassetti , Alberto Oliva

We attribute the recently discovered cosmic ray electron and cosmic ray positron excess components and their cutoffs to the acceleration in the supernova shock in the polar cap of exploding Wolf Rayet and Red Super Giant stars. Considering…

High Energy Astrophysical Phenomena · Physics 2009-09-02 P. L. Biermann , J. K. Becker , A. Meli , W. Rhode , E. -S. Seo , T. Stanev

This is the first of a series of papers analysing the Galactic Cosmic Ray composition and origin. We show that the Galactic Cosmic Ray source (GCRS) composition is best described in terms of (i) a general enhancement of the refractory…

Astrophysics · Physics 2009-10-30 Jean-Paul Meyer , L. O'C. Drury , Donald C. Ellison

The origin of cosmic rays is one of the major unresolved astrophysical questions. In particular, the highest energy cosmic rays observed possess macroscopic energies and their origin is likely to be associated with the most energetic…

Astrophysics · Physics 2007-05-23 Guenter Sigl

The spectral shape of cosmic ray positrons and antiprotons has been accurately measured in the broad kinetic energy range 1-350 GeV. In the higher part of this range (E > 30 GeV) the e+ and pbar are both well described by power laws with…

High Energy Astrophysical Phenomena · Physics 2017-03-15 Paolo Lipari

The existence of cosmic ray particles up to the ultra-high energy limit (> 10^20 eV) is now beyond any doubt. The detection of cosmic particles with such energies imposes a challenge for the comprehension of their sources and nature. On one…

Ongoing experimental efforts to detect cosmic sources of high energy neutrinos are guided by the expectation that astrophysical accelerators of cosmic ray protons would also generate neutrinos through interactions with ambient matter and/or…

Astrophysics · Physics 2014-10-13 Luis A. Anchordoqui , Dan Hooper , Subir Sarkar , Andrew M. Taylor

It is now widely acknowledged that cosmic rays experiments can test possible new physics directly generated at the Planck scale or at some other fundamental scale. By studying particle properties at energies far beyond the reach of any…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Luis Gonzalez-Mestres

It is generally regarded that the bulk of cosmic rays originate in the Galaxy and that those below the 'knee' (the rapid steepening in the energy spectrum) at a few PeV come from Galactic supernovae, the particles being accelerated by the…

Astrophysics · Physics 2009-11-13 A. D. Erlykin , A. W. Wolfendale

The excess of continuum gamma-ray emission from the Galaxy above 1 GeV is an unsolved puzzle. It may indicate that the interstellar nucleon or electron spectra are harder than local direct measurements, as could be the case if a local…

Astrophysics · Physics 2011-05-23 I. V. Moskalenko , A. W. Strong , O. Reimer

Cosmic-ray positrons have long been considered a powerful probe of dark matter annihilation. In particular, myriad studies of the unexpected rise in the positron fraction have debated its dark matter or pulsar origins. In this paper, we…

High Energy Astrophysical Phenomena · Physics 2022-01-07 Isabelle John , Tim Linden

This paper deals with the cosmic-ray penetration into molecular clouds and with the related gamma--ray emission. High energy cosmic rays interact with the dense gas and produce neutral pions which in turn decay into two gamma rays. This…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Stefano Gabici

AMS instrument aboard the International Space Station is a high precision instrument capable of collecting large statistics on cosmic ray intensities and as such has started making highly significant contributions to Astroparticle Physics.…

High Energy Astrophysical Phenomena · Physics 2015-06-15 R. Cowsik , B. Burch , T. Madziwa-Nussinov

Cosmic rays are relativistic particles that come to the Earth from outer space. Despite a great effort made in both experimental and theoretical research, their origin is still unknown. One of the main keys to understand their nature is the…

High Energy Astrophysical Phenomena · Physics 2022-12-23 A. D. Supanitsky

The physics of energetic particle propagation in magnetised environments plays a crucial role in both the processes of acceleration and transport of cosmic rays. Recent theoretical developments in the field of cosmic ray research have been…

High Energy Astrophysical Phenomena · Physics 2018-10-31 Elena Amato , Pasquale Blasi

The AMS-02 experiment confirms the excess of positrons in cosmic rays (CRs) for energy above 10 GeV with respect to the secondary production of positrons in the interstellar medium. This is interpreted as evidence of the existence of a…

High Energy Astrophysical Phenomena · Physics 2017-08-23 S Della Torre , M Gervasi , PG Rancoita , D Rozza , A Treves
‹ Prev 1 3 4 5 6 7 10 Next ›