REVIEW OF DARK MATTER EXPERIMENTS

The non-luminous matter constituting probably more than 90% of the mass of the universe cannot be any particle in the Standard Model of particle physics. Non-accelerator experiments, particularly those using Ge and Si detectors, and accelerator experiments at SLC and LEP, have eliminated as dark matter wide classes of candidate particles, spanning 12 orders of magnitude in mass and 20 orders of magnitude in cross section. Examples are weak isodoublet neutrinos greater than or similar to 30 eV/c2, sneutrinos, technibaryons, microcharged shadow matter, and Cosmions, which could be both dark matter and solve the solar neutrino problem. Isodoublet neutrinos of all masses are eliminated if the 17-keV neutrino exists. A remaining candidate, the lightest supersymmetric particle (LSP), can be searched for with cryogenic detectors having potentially two orders of magnitude greater sensitivity than ionization detectors, as both ionization and phonons can be measured. The nuclear recoil signal produces mainly phonons, whereas the main background (electrons from Compton scattering and beta decay) produces mainly ionization. Enriched Ge-73 (spin 9/2) will be used to look for the LSP.