Dark Matter Searches with Astroparticle Data

TL;DR

This paper reviews the current status of astroparticle experiments searching for dark matter, focusing on gamma-ray signals and the interpretation of experimental results in the context of WIMP models.

Contribution

It provides a comprehensive overview of observational searches for dark matter using gamma-ray telescopes and discusses the implications for dark matter particle properties.

Findings

No definitive dark matter detection yet.

Constraints on WIMP annihilation cross-sections.

Potential signals require further evidence.

Abstract

The existence of dark matter (DM) was first noticed by Zwicky in the 1930s, but its nature remains one of the great unsolved problems of physics. A variety of observations indicate that it is non-baryonic and non-relativistic. One of the preferred candidates for non-baryonic DM is a weakly interacting massive particle (WIMP) that in most models is stable. WIMP self-annihilation can produce cosmic rays, gamma rays, and other particles with signatures that may be detectable. Hints of anomalous cosmic-ray spectra found by recent experiments, such as PAMELA, have motivated interesting interpretations in terms of DM annihilation and/or decay. However, these signatures also have standard astrophysical interpretations, so additional evidence is needed in order to make a case for detection of DM annihilation or decay. Searches by the Fermi Large Area Telescope for gamma-ray signals from clumps, nearby dwarf spheroidal galaxies, and galaxy clusters have also been performed, along with measurements of the diffuse Galactic and extragalactic gamma-ray emission. In addition, imaging atmospheric Cherenkov telescopes like HESS, MAGIC, and VERITAS have reported on searches for gamma-ray emission from dwarf galaxies. In this review, we examine the status of searches for particle DM by these instruments and discuss the interpretations and resulting DM limits.