2004/08/31 by P. Fayet, Fayet, P. · 1 citation
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/0408357
14 pages, Proc. 39th Rencontres de Moriond ``Exploring the Universe'', La Thuile, Italy (march 28 - april 4, 2004)
arxiv created 2004/08/31 · arxiv updated 2009/12/01
We show how light spin-1/2 or spin-0 particles may be acceptable Dark Matter candidates, provided they annihilate sufficiently strongly through new interactions, such as those induced by a new light neutral spin-1 boson U. The corresponding interaction is stronger than weak interactions at lower energies, but weaker at higher energies. Annihilation cross sections of (axially coupled) spin-1/2 Dark Matter particles, induced by a U vectorially coupled to matter, are the same as for spin-0 particles. In both cases, the cross sections (sigma vrel/c) into e+e- automatically include a vdm2 suppression factor, as desirable to avoid an excessive production of gamma rays from residual Dark Matter annihilations. We also relate Dark Matter annihilations with production cross sections in e+e- reactions. As for spin-0, light spin-1/2 Dark Matter particles annihilating into e+e- could be responsible for the bright 511 keV gamma ray line observed by INTEGRAL from the galactic bulge.