Dark Matter Evidence, Particle Physics Candidates and Detection Methods

TL;DR

This paper reviews the evidence for dark matter, explores particle candidates like WIMPs, and discusses detection methods including accelerator, direct, and indirect detection, highlighting recent potential signals and future prospects.

Contribution

It provides a comprehensive overview of dark matter candidates, detection techniques, and recent experimental hints, emphasizing the importance of upcoming experiments to confirm or refute WIMPs as dark matter.

Findings

Possible indications of dark matter signals in direct detection experiments.

Potential gamma-ray signal at 130 GeV from Fermi-LAT data.

Future experiments may confirm or rule out WIMPs as dark matter candidates.

Abstract

The problem of the dark matter in the universe is reviewed. A short history of the subject is given, and several of the most obvious particle candidates for dark matter are identified. Particular focus is given to weakly interacting, massive particles (WIMPs) of which the lightest supersymmetric particle is an interesting special case and a usful template. The three detection methods: in particle accelerators, by direct detection of scattering in terrestrial detectors, and indirect detection of products from dark matter particle annihilation in the galactic halo, are discussed and their complementarity is explained. Direct detection experiments have revealed some possible indications of a dark matter signal, but the situation is quite confusing at the moment. Very recently, also indirect detection has entered a sensitivity region where some particle candidates could be detectable. Indeed, also here there are some (presently non-conclusive) indications of possible dark matter signals, like an interesting structure at 130 GeV gamma-ray energy found in publicly available data from the Fermi-LAT space detector. The future of the field will depend on whether WIMPs are indeed the dark matter, something that may realistically be probed in the next few years. If this exciting scenario turns out to be true, we can expect a host of other, complementary experiments in the coming decade. If it is not true, the time scale and methods for detection will be much more uncertain.