XXth International Conference on Neutrino Physics and Astrophysics
S.Elliott for the Majorana Collaboration
The Majorana 76Ge Double Beta Decay Project
The interest and relevance of next-generation 0nu beta-beta-decay
experiments is increasing. Even with nonzero neutrino mass strongly
suggested by solar and atmospheric neutrino experiments sensitive to
delta m^2, 0nu beta-beta-decay experiments are still the only way to
establish the Dirac or Majorana nature of neutrinos by measuring the
effective electron neutrino mass, . In addition, the atmospheric
neutrino oscillation experiments imply that at least one neutrino has
a mass greater than about 50 meV. The Majorana Experiment expects to
probe an effective neutrino mass near this critical value.
Majorana is a next-generation 76Ge double-beta decay search. It will
employ 500 kg of Ge, isotopically enriched to 86% in 76Ge, in the form
of ~200 detectors in a close-packed array. Each crystal will be
electronically segmented and each segment fitted with pulse-shape
analysis electronics. This combination of segmentation and
pulse-shape analysis significantly improves our ability to
discriminate neutrinoless double beta-decay from internal cosmogenic
68Ge and 60Co. The half-life sensitivity is estimated to be 4x10^27 y
corresponding to a range of < 20-70 meV, depending on the
nuclear matrix elements used to interpret the data.
Based on hep-ex/0201021