English

Initial State Radiation in Majorana Dark Matter Annihilations

High Energy Physics - Phenomenology 2011-10-27 v1

Abstract

The cross section for a Majorana Dark Matter particle annihilating into light fermions is helicity suppressed. We show that, if the Dark Matter is the neutral Majorana component of a multiplet which is charged under the electroweak interactions of the Standard Model, the emission of gauge bosons from the initial state lifts the suppression and allows an s-wave annihilation. The resulting energy spectra of stable Standard Model particles are importantly affected. This has an impact on indirect searches for Dark Matter.

Keywords

Cite

@article{arxiv.1107.4453,
  title  = {Initial State Radiation in Majorana Dark Matter Annihilations},
  author = {Paolo Ciafaloni and Marco Cirelli and Denis Comelli and Andrea De Simone and Antonio Riotto and Alfredo Urbano},
  journal= {arXiv preprint arXiv:1107.4453},
  year   = {2011}
}

Comments

9 pages, 3 figures

R2 v1 2026-06-21T18:40:27.875Z