The Majorana 76
Ge double-beta decay project
The interest and relevance of next-generation 0 ν ββ-decay experiments is increasing. Even with nonzero neutrino mass strongly suggested by solar and atmospheric neutrino experiments sensitive to δm 2 , 0 ν ββ-decay experiments are still the only way to establish the Dirac or Majorana nature of neutrinos by measuring the effective electron neutrino mass, 〈m ν 〉. 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 76 Ge double-beta decay search. It will employ 500 kg of Ge, isotopically enriched to 86% in 76 Ge, 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 68 Ge and 60 Co. The half-life sensitivity is estimated to be 4.2 × 10 27 y corresponding to a 〈m ν 〉 range of ≤ 20-70 meV, depending on the nuclear matrix elements used to interpret the data.
Aalseth, CE; Adles, E; Anderson, D; Avignone, FT; Barabash, A; Bowyer, TW; Brodzinski, RL; Brudanin, V; Champangne, A; Collar, JI; Doe, PJ; Egorov, S; Elliott, SR; Farach, HA; Gaitskell, R; Jordan, D; Jain, RK; Kazkaz, K; King, G; Kochetov, O; Konovalov, S; Kouzes, R; Miley, HS; Palms, JM; Pitts, WK; Reeves, JH; Robertson, RGH; Rohm, R; Sandukovsky, S; Smith, LE; Stekhanov, V; Thompson, RC; Tornow, W; Umatov, V; Warner, R; Webb, J; Wilkerson, JF; Young, A
Volume / Issue
Start / End Page
International Standard Serial Number (ISSN)
Digital Object Identifier (DOI)