Positron/Gamma-Ray Signatures of Dark Matter Annihilation and Big-Bang Nucleosynthesis

TL;DR

This paper explores how dark matter annihilation could explain the positron excess and cosmic lithium discrepancies, with potential confirmation from Fermi satellite data.

Contribution

It demonstrates that dark matter annihilation scenarios can simultaneously account for positron excess and lithium abundance discrepancies, exemplified by the wino-like neutralino.

Findings

Dark matter annihilation can explain positron excess.

Such scenarios may resolve lithium abundance discrepancies.

Fermi satellite could confirm these models.

Abstract

The positron excess observed by the PAMELA experiment may come from dark matter annihilation, if the annihilation cross section is large enough. We show that the dark matter annihilation scenarios to explain the positron excess may also be compatible with the discrepancy of the cosmic lithium abundances between theory and observations. The wino-like neutralino in the supersymmetric standard model is a good example for it. This scenario may be confirmed by Fermi satellite experiment.