Results of the MAJORANA DEMONSTRATOR's Search for Double-Beta Decay of 76Ge to Excited States of 76Se. (February 2020)

• Record Type: Journal Article
• Authors: Guinn, I.S.; Arnquist, I.J.; Avignone, F.T.; Barabash, A.S.; Barton, C. J.; Bertrand, F.E.; Bos, B.; Busch, M.; Buuck, M.; Caldwell, T.S.; Chan, Y-D.; Christofferson, C.D.; Chu, P-H.; Clark, M.L.; Cuesta, C.; Detwiler, J.A.; Drobizhev, A.; Edwins, D. W.; Efremenko, Yu.; Ejiri, H.; Elliott, S.R.; Gilliss, T.; Giovanetti, G.K.; Green, M.P.; Gruszko, J.; Guiseppe, V.E.; Haufe, C.R.; Hegedus, R.J.; Henning, R.; Hervas Aguilar, D.; Hoppe, E.W.; Hostiuc, A.; Kidd, M.F.; Kim, I.; Kouzes, R.T.; Lopez, A.M.; López-Castaño, J.M.; Martin, E. L.; Martin, R.D.; Massarczyk, R.; Meijer, S.J.; Mertens, S.; Myslik, J.; Oli, T.K.; Othman, G.; Pettus, W.; Poon, A.W.P.; Radford, D.C.; Rager, J.; Reine, A.L.; Rielage, K.; Ruof, N.W.; Stortini, M.J.; Tedeschi, D.; Varner, R.L.; Wilkerson, J.F.; Wiseman, C.; Xu, W.; Yu, C.-H.; Zhu, B.X.;
• Is Part Of: Journal of physics. Volume 1468(2020)
• Publication Date: 2020-02
• Subjects: Physics -- Congresses; 530.5
• DOI: 10.1088/1742-6596/1468/1/012115
• Languages: English
• ISSNs: 1742-6588

Abstract

Abstract: The MAJORANA DEMONSTRATOR is searching for double-beta decay of 76 Ge to excited states (E.S.) in 76 Se using a modular array of high purity Germanium detectors. 76 Ge can decay into three E.S.s of 76 Se. The E.S. decays have a clear event signature consisting of a ββ -decay with the prompt emission of one or two γ -rays, resulting in with high probability in a multi-site event. The granularity of the DEMONSTRATOR detector array enables powerful discrimination of this event signature from backgrounds. Using 21.3 kg-y of isotopic exposure, the DEMONSTRATOR has set world leading limits for each E.S. decay, with 90% CL lower half-life limits in the range of (0.56 ‒ 2.1) ⋅ 10 24 y. In particular, for the 2 v transition to the first 0 + E.S. of 76 Se, a lower half-life limit of 0.68 ⋅ 10 24 at 90% CL was achieved.