New cryogenic detectors probe recent evidence for dark matter particles Researchers from 10 institutions reported today that they have achieved the world's best discrimination in the search for dark matter, which scientists have postulated makes up more than 90 percent of the mass of the universe. This discrimination allows an unambiguous identification of events in the crystals caused by any new form of matter. Calif. Within the currently favored theoretical models these results appear incompatible with the evidence for dark matter reported by the DAMA collaboration last week. The two searches use very different techniques for detecting dark matter particles. The research is supported jointly by the Department of Energy and by the National Science Foundation in a collaboration coordinated by the Center for Particle Astrophysics.
Most supersymmetric models predict the existence of such particles, which are called neutralinos.
The neutralinos and their interaction rates are at or below this level. The discovery of WIMPs would confirm 70 years of combined astrophysics and particle physics research that suggests most of the matter of the universe is dark and is not made of ordinary atoms. The existence of WIMPs is predicted from very general considerations about the big bang and the early universe. Last week, the DAMA collaboration reported on more than three years of data collected with a 100-kilogram sodium iodide detector operated deep underground in the Gran Sasso National Laboratory in Italy. Their detector produces a flash of light each time there is a particle interaction within its volume.