1999/01/31 by Pasquale Blasi · 3 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Dark Matter and Cosmic Phenomena #Particle physics theoretical and experimental studies #astro-ph
paper · pdf · doi:10.1103/physrevd.60.023514
published as Phys.Rev. D60 (1999) 023514 · version accepted for publication in Phys. Rev. D
arxiv created 1999/05/15 · openalex publication_date 1999/06/23 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Superheavy (SH) quasistable particles generated in the early universe could be responsable for ultrahigh energy cosmic rays (UHECRs) and be a component of cold dark matter in the universe. These particles are likely to cluster in the galactic halo, so that the main part of UHECRs are gamma rays produced in the decay of neutral pions. Charged pions are also produced in the same process and result in high energy electrons. We consider here the production of gamma rays by synchrotron emission of these electrons in the galactic magnetic field. The gamma ray fluxes are in the region of interest for some current and proposed experiments (e.g. EGRET, GLAST, MILAGRO) in the energy range 0.1--104 GeV. A comparison with the existing upper limits at 105--108 GeV is also carried out. The detection of this flux of gamma rays would be an important signature of SH relic particles as sources of UHECRs and would give a clue to the physics of the early universe.