LEGEND Collaboration Meeting: Neutrinoless Double Beta Decay and the LEGEND Project

  • Date May 15, 2017
  • Hour 5 pm
  • Room GSSI Main Lecture Hall
  • Speaker Steven R. Elliott (Los Alamos National laboratory)


At least one neutrino has a mass of about 45 meV or larger. However, the absolute mass scale for the neutrino is unknown. Furthermore, the critical question: Is the neutrino its own antiparticle? remains unanswered. Studies of double beta decay will contribute to our understanding of the absolute mass scale. In particular, zero-neutrino double beta decay (0nbb) can address the issues of lepton number conservation, the particle-antiparticle nature of the neutrino, and its mass. Recent experimental results have demonstrated the increasing reach of the technologies used to search for 0nbb. In addition, theoretical progress in understanding the nuclear physics involved has also been impressive. All indications are that upcoming generations of 0nbb experiments will be sensitive to neutrino masses in the exciting range below 45 meV.

The half-life of 0nbb is directly related to the effective neutrino mass. But the half-life is very long; at least greater than 1025 years. Hence any search for the rare peak in a spectrum resulting from 0nbb must minimize the background of other processes that may take place in a detector. Ge-detector based experiments have established the best background levels to date and are a promising technology for the future. A summary of the physics of 0nbb, and the related technologies will be discussed in the context of past 76Ge experiments and a future 0nbb program using that isotope.