2008/10/31 by Manuel Masip, Iacopo Mastromatteo · 10 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Baryonic dark matter #Cosmic ray #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark matter #Flux (metallurgy) #Galaxy #Light dark matter #Proton #Scalar field dark matter #Ultra-high-energy cosmic ray #astro-ph #hep-ph
paper · pdf · doi:10.1088/1475-7516/2008/12/003
published in Journal of Cosmology and Astroparticle Physics 2008(12), 003 (Institute of Physics) · 19 pages, references added, version to appear in JCAP
arxiv created 2008/11/11 · openalex publication_date 2008/12/01 · arxiv updated 2010/04/21 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
In models with extra dimensions the fundamental scale of gravity M D could be of the order of TeV. In that case the interaction cross section between a cosmic proton of energy E and a dark matter particle χ will grow fast with E for center-of-mass energies above M D , and it could reach 1 mbarn at E ≈10 9 GeV. We show that these gravity-mediated processes would break the proton and produce a diffuse flux of particles/antiparticles, while boosting χ with a fraction of the initial proton energy. We find that the expected cross sections and dark matter densities are not enough to produce an observable asymmetry in the flux of the most energetic (extragalactic) cosmic rays. However, we propose that unsuppressed TeV interactions may be the origin of the knee observed in the spectrum of galactic cosmic rays. The knee would appear at the energy threshold for the interaction of dark matter particles with cosmic protons trapped in the galaxy by µG magnetic fields, and it would imply a well-defined flux of secondary antiparticles and TeV gamma rays.