Particle and Astroparticle Physics Seminar

Search for neutrinoless double-beta decay in ⁷⁶Ge

Alan Poon

Nuclear Science Division
Lawrence Berkeley National Laboratory

Neutrinoless double-beta decay is a forbidden, lepton-number-violating nuclear transition whose observation would have fundamental implications for neutrino physics, theories beyond the Standard Model, and cosmology. In this isobaric transition, the parent nucleus decays to the daughter nucleus two nuclear charges away with the emission of two electrons, but no (anti)neutrinos. The current generation of experiments exploit the uniqueness and physical characteristics of several isotopes. In this talk, I will describe the experimental program that deploys ⁷⁶Ge-enriched high-purity germanium detectors, particularly the current-generation Majorana Demonstrator experiment and the next-generation LEGEND experiment. This latter project will improve on the discovery potential at a half-life beyond 10²⁸ years, or two orders of magnitude improvement over existing experiments.