Related papers: The science of PAMELA space mission
Two of the most compelling issues facing astrophysics and cosmology today are to understand the nature of the dark matter that pervades the universe and to understand the apparent absence of cosmological antimatter. For both issues,…
Positrons are known to be produced in interactions between cosmic-ray nuclei and interstellar matter ("secondary production"). Positrons may, however, also be created by dark matter particle annihilations in the galactic halo or in the…
Very recently, PAMELA Collaboration has formally reported two sets of data on positron and antiproton flux measurements done at very high energies and with unprecedented accuracy. The reports reveal a puzzle of great topical interest and…
Using an effective interaction approach to describe the interactions between the dark matter particle and the light degrees of freedom of the standard model, we calculate the antiproton flux due to the annihilation of the dark matter in the…
Antiprotons are regarded as a powerful probe for Dark Matter (DM) indirect detection and indeed current data from PAMELA have been shown to lead to stringent constraints. However, in order to exploit their constraining/discovery power…
The possibility of creation of cosmologically significant antimatter are analyzed in different scenarios of baryogenesis. It is argued that there may exist plenty of antimatter even in our Galaxy. Possible forms of antimatter objects and…
Cosmological models which predict a large amount of antimatter in the Universe are reviewed. Observational signatures and searches for cosmic antimatter are briefly considered. A short discussion of new long range forces which might be…
Studying the acceleration and propagation mechanisms of Galactic cosmic rays can provide information regarding astrophysical sources, the properties of our Galaxy, and possible exotic sources such as dark matter. To understand cosmic ray…
A possible existence of cosmologically large domains of antimatter or astronomical ``anti-objects'' is discussed. A brief review of different scenarios of baryogenesis predicting a noticeable amount of antimatter is given. Though both…
We review gamma-ray observations that constrain antimatter - both baryonic and leptonic - in the Universe. Antimatter can be probed through ordinary matter, with the resulting annihilation gamma-rays providing indirect evidence for its…
Over the last three years, several satellite and balloon observatories have suggested intriguing features in the cosmic ray lepton spectra. Most notably, the PAMELA satellite has suggested an "anomalous" rise with energy of the cosmic ray…
The astronomical dark matter could be made of weakly interacting massive species whose mutual annihilations should produce antimatter particles and distortions in the corresponding energy spectra. The propagation of cosmic rays inside the…
The whole set of astrophysical data indicates that our Universe is globally baryon asymmetrical. Nevertheless a possibility of existence of relatively small amount of sufficiently large antimatter regions is not excluded. Such regions can…
A recently proposed model (arXiv:0903.2794) explains the rise in energy of the positron fraction measured by the PAMELA satellite in terms of hadronic production of positrons in aged supernova remnants, and acceleration therein. Here we…
The satellite-borne experiment PAMELA has been used to make a new measurement of the cosmic-ray antiproton flux and the antiproton-to-proton flux ratio which extends previously published measurements down to 60 MeV and up to 180 GeV in…
Possible mechanisms of baryogenesis are reviewed. Special attention is payed to those which allow for creation of astronomically significant domains or objects consisting of antimatter. Observational manifestations of cosmological…
The detection of gamma-rays, antiprotons and positrons due to pair annihilation of dark matter particles in the Milky Way halo is a viable indirect technique to search for signatures of supersymmetric dark matter where the major challenge…
PAMELA is a satellite borne experiment designed to study with great accuracy cosmic rays of galactic, solar, and trapped nature in a wide energy range (protons: 80 MeV-700 GeV, electrons 50 MeV-400 GeV). Main objective is the study of the…
We review observational evidence for a matter-antimatter asymmetry in the early universe, which leads to the remnant matter density we observe today. We also discuss observational bounds on the presence of antimatter in the present day…
Recent measurements of cosmic ray leptons by PAMELA, ATIC, HESS and Fermi revealed interesting excesses. Many authors suggested particle Dark Matter (DM) annihilations could be at the origin of these effects. In this paper, we critically…