Indirect Dark Matter Searches in the Light of ATIC, FERMI, EGRET and PAMELA

TL;DR

Recent cosmic ray data from multiple observatories show anomalies in positron and electron spectra, prompting various explanations including dark matter annihilation, but the lack of corresponding antiproton or gamma-ray excesses challenges some models.

Contribution

The paper reviews recent cosmic ray observations and discusses the implications for dark matter models, especially leptophilic WIMPs, in light of new experimental data.

Findings

Positron excess observed without corresponding antiproton excess.

Leptophilic dark matter models are considered to explain positron anomalies.

Spectral shape of positron fraction matches proton background expectations.

Abstract

Recently, new data on antiprotons and positrons from PAMELA, e- + e+ spectra from ATIC, FERMI and HESS up to TeV energies all indicate deviations from expectations, which has caused an interesting mix of new explanations, ranging from background, standard astrophysical sources to signals from dark matter (DM) annihilation. Unfortunately, the excess in positrons is not matched with obvious excesses in antiprotons or gamma rays, so a new class of DM scenarios with leptophilic WIMP candidates have been invoked. On the other hand, the increase in the positron fraction, which could have had any spectral shape for new physics, matches well the shape expected from proton background.