The Majorana Experiment will perform an essentially background-free measurement of neutrinoless double-beta decay (0νββ) in 120 kg of 76Ge with the goal of determining the neutrino mass.
Neutrinoless double-beta decay provides the physics community with the opportunity to build on our successes in understanding the neutrino and crafting a new standard model. With the results from Super-Kamiokande, SNO, KamLAND, and other neutrino experiments we have demonstrated that neutrinos are massive, change flavor, and play an important role in the universe. These results have yielded the first physics beyond the standard model in nearly four decades. Even with these impressive results, neutrinos continue to provide some of the most exciting opportunities in understanding our universe. Theoretical prejudices for Majorana neutrinos have existed for decades and neutrinoless double-beta decay is the only practical technique that can determine whether neutrinos are Majorana or Dirac particles.
For the first time we can mount experiments that probe the neutrino-mass region below the upper limits set by direct kinematical searches (tritium decay) and suggested by observational cosmology, while planning scaled approaches that can address the lower bounds of mass defined by the atmospheric and solar plus reactor neutrino oscillation experiments.