The discovery of neutrino mass is the first tangible contradiction of the Standard Model of particle physics. Two neutrino double-beta decay (2νββ) is an allowed second order process in the Standard Model that has been observed with half-lives in the range of 10^18 − 10^24 y. Because it involves two neutrino vertices, double-beta ...

Neutrinoless double-beta decay (0vbb) is a lepton-number-violating process whose existence would indicate that neutrinos are Majorana fermions. The MAJORANA collaboration is searching for 0vbb in germanium-76 using a modular array of high-purity germanium (HPGe) detectors with support and shielding constructed from low-background ...