This award will enable the group to continue a comprehensive program in neutrino-less double-beta decay (NDBD). The intellectual merit of this activity is based on the fact that NDBD is the only practical way to determine if neutrinos are Majorana particles (their own antiparticles). This exotic decay is the most sensitive test of lepton number conservation, an important symmetry in elementary-particle physics. If indeed neutrinos are Majorana particles, a measurement of the NDBD half-life would yield the effective Majorana mass of the electron neutrino. Combined with neutrino oscillation data, it would determine all three neutrino mass eigenvalues. Leptogenesis in the early universe is only possible if there are Majorana neutrinos. The laboratory observation and measurement of NDBD would be transformative of elementary particle physics, astrophysics and cosmology.
The group is working on two NDBD experiments: CUORE and MAJORANA. USC has the major tasks of the procurement, production, installation, and maintenance of the front-end CUORE electronic system from the detector to the data acquisition system, and is involved in the construction and operation of CUORE-0, the first tower of CUORE. USC leads a major Task in the MAJORANA DEMONSTRATOR R&D which has the responsibility for the procurement of enriched germanium oxide, its reduction to metal, zone refinement to detector quality metal, and reprocessing of scrap material. USC led the construction and operation of the facility for the germanium (Ge) processing.
Broader Impacts: Discovery would make important contributions to astrophysics and cosmology. New Ge-detector technology developed in this program is now used in National and Homeland security. Students are being trained in cryogenic technology for other basic and applied sciences and in advanced computational methods. The USC group has a new program of outreach to high school students and teachers.
