Nuclear Particle Astrophysics (NPA) Seminar: Walter Pettus, Univesrity of Washington, “LEGEND in the Making: The 76Ge Program for Neutrinoless Double Beta Decay”

Neutrinoless double-beta decay (0νββ) is a hypothetical lepton-number violating process that would establish the Majorana nature of neutrinos. Interpreting a positive result will have widespread implications - as an indirect probe of neutrino mass, a demonstration of new physics beyond the Standard Model, and hint at resolution to the matter-antimatter asymmetry in the universe. The presently operating 76Ge experiments, GERDA and the Majorana Demonstrator, have achieved world-leading results and performed technical demonstrations that advance the continuing program. Building on these successes, LEGEND will follow a staged experimental program. LEGEND-200 is preparing to operate 200 kg of 76Ge-enriched detectors in 2021 using existing infrastructure at LNGS. The subsequent LEGEND-1000 is a ton-scale experiment that will have 10^28 year sensitivity to probe the inverted hierarchy allowed region.