Increasing the Neutralino Relic Abundance with Slepton Coannihilations: Consequences for Indirect Dark Matter Detection
arXiv:hep-ph/0609290 · doi:10.1088/1475-7516/2006/12/019
Abstract
We point out that if the lightest supersymmetric particle (LSP) is a Higgsino- or Wino-like neutralino, the net effect of coannihilations with sleptons is to increase the relic abundance, rather than producing the usual suppression, which takes place if the LSP is Bino-like. The reason for the enhancement lies in the effective thermally averaged cross section at freeze-out: sleptons annihilate (and co-annihilate) less efficiently than the neutralino(s)-chargino system, therefore slepton coannihilations effectively act as parasite degrees of freedom at freeze-out. Henceforth, the thermal relic abundance of LSP's corresponds to the cold Dark Matter abundance for smaller values of the LSP mass, and larger values of the neutralino pair annihilation cross section. In turn, at a given thermal neutralino relic abundance, this implies larger indirect detection rates, as a result of an increase in the fluxes of antimatter, gamma rays and neutrinos from the Sun orginating from neutralino pair annihilations.
16 pages, 6 figures, references added, typos corrected, matches with the published version
References in corpus (6)
- PAMELA - A Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics
- Neutralino Dark Matter Detection in Split Supersymmetry Scenarios
- The Role of Antimatter Searches in the Hunt for Supersymmetric Dark Matter
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Cited by in corpus (6)
- Dark Matter and Collider Phenomenology of Universal Extra Dimensions
- New Gamma-Ray Contributions to Supersymmetric Dark Matter Annihilation
- Recoil Detection of the Lightest Neutralino in MSSM Singlet Extensions
- Explaining PAMELA and WMAP data through Coannihilations in Extended SUGRA with Collider Implications
- Dark matter from late decays and the small-scale structure problems
- Discriminating dark matter candidates using direct detection