Direct Detection of WIMPs

In the next chapters we are going to give an overview of the main WIMP search strategies, which fall in three big categories: • Direct searches probe the scattering cross section of WIMPs with nuclei, by looking for nuclear recoils in some target material in a low background environment. When a WIMP of the galactic halo passes through the target, it may scatter off a nucleus, whose recoil will be measured by suitable detectors. The main astrophysical uncertainty is due to the DM density in the Solar System and to its velocity distribution. • Indirect searches look for the products of WIMP annihilations in a number of astrophysical objects, including the galaxy and his satellites, other galaxies and galaxy clusters, as well as the Sun and the Earth. • In LHC searches, DM particles (and generically the “dark sector”) are studied by producing them in proton collisions, in association with other SM particles (being very weakly interacting, WIMPs would otherwise be invisible at colliders, and their typical signature is missing energy in the transverse plane).