Decoding the nature of Dark Matter in current and future experiments

by Alexander Belyaev (RAL/Southampton University)


The nature of Dark Matter (DM) is one of the greatest puzzles of modern particle physics and cosmology. Although overwhelming observational evidences from galactic to cosmological scales point to the existence of DM, after decades of experimental effort only its gravitational interaction has been experimentally confirmed. Currently, no information is available on the DM properties, such as its spin, mass, interactions other than gravitational, symmetry responsible for its stability, number of states associated to it, and possible particles that would mediate the interactions between DM and the standard model (SM) particles.

If DM is light enough and interacts with SM particles directly or via some mediators with a strength beyond the gravitational one, its elusive nature can be detected or constrained in different ways:

a) from direct production at colliders, resulting in a signature exhibiting an observed SM particles that recoils against the missing energy from the DM pair;

b) via the relic density constraint obtained through the observations of cosmic microwave background (CMB) anisotropies, such as those of WMAP and PLANCK collaborations;

c) from DM direct detection (DD) experiments, which are sensitive to elastic spin independent (SI) or spin dependent (SD) DM scattering off nuclei;

d) from DM indirect detection searches, that look for SM particles produced in the decay or annihilation of DM present in the cosmos, both with high energies observables (gamma-rays, neutrinos, charge cosmic rays) produced in the local Universe , and by studying the effects of energy produced by DM annihilation in the early universe on the properties of the CMB spectrum.

Decoding of the nature of DM requires the respective signal in at least one of the search experiments. So far we did not observe any. However, even without having signal at the moment we can already conclude on what kind of DM models are excluded. Moreover, using properties of different signatures from one particular model, their correlation and interplay we can prepare ourselves to discovery of DM and their identification. The current status and the future prospects of this problem will be discussed in my talk.