Experimental Particle Cosmology

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

PROPOSAL NUMBER: 0802575 INSTITUTION: University of California ? Berkeley NSF PROGRAM: PHY ? UNDERGROUND PHYSICS PRINCIPAL INVESTIGATOR: Sadoulet, Bernard TITLE: Experimental Particle Cosmology ABSTRACT A broad range of observations, from galaxies and superclusters to distant supernovae and the cosmic microwave background radiation, tell us that about 85% of the matter in the universe is not made of ordinary particles, but exists in some dark form. Deciphering the nature of this dark matter is of fundamental importance to cosmology, astrophysics, and high-energy particle physics. A leading hypothesis is that it is comprised of Weakly Interacting Massive Particles, or WIMPs, that were produced moments after the Big Bang. If WIMPs exist and are the dark matter, then their presence in our Milky Way may be detectable via scattering from atomic nuclei in a terrestrial detector. This proposal requests the renewal of the base program of the UC Berkeley group to support their participation in the Cryogenic Dark Matter Search (CDMS) CDMS-II & SuperCDMS 25 kg projects. This includes (a) the completion of the CDMS-II experiment, which is fully constructed and acquiring science data at the Soudan Mine in Minnesota, and (b) the testing and underground operation in the CDMS-II infrastructure at Soudan of two new SuperTowers. This program will have broader impact than improving limits or detecting WIMPs. Not only are its scientific results important for astrophysics and particle physics, but its technological development will also push the envelope of phonon-mediated detectors, whose applications are increasingly widespread, and contribute to the development of non-dissipative readout techniques. Furthermore, they continue to support the public outreach program at Soudan, which hosts some 60,000 visitors and tens of classes each year for tours of the mine and laboratory.