Search for Tri-Nucleon Decay in the Majorana Demonstrator

• Main Authors: Alvis, S. I, Arnquist, I. J, AvignoneIII, F. T, Barabash, A. S, Barton, C. J, Bertrand, F. E, Bos, B, Brudanin, V, Busch, M, Buuck, M, Caldwell, T. S, Chan, Y-D, Christofferson, C. D, Chu, P. -H, Cuesta, C, Detwiler, J. A, Efremenko, Yu, Ejiri, H, Elliott, S. R, Gilliss, T, Giovanetti, G. K, Green, M. P, Gruszko, J, Guinn, I. S, Guiseppe, V. E, Haufe, C. R, Hegedus, R. J, Hehn, L, Henning, R, Aguilar, D. Hervas, Hoppe, E. W, Howe, M. A, Keeter, K. J, Kidd, M. F, Konovalov, S. I, Kouzes, R. T, Lopez, A. M, Martin, R. D, Massarczyk, R, Meijer, S. J, Mertens, S, Myslik, J, Othman, G, Pettus, W, Piliounis, A, Poon, A. W. P, Radford, D. C, Rager, J, Reine, A. L, Rielage, K, Ruof, N. W, Shanks, B, Shirchenko, M, Tedeschi, D, Varner, R. L, Vasilyev, S, Vasundhara, White, B. R, Wilkerson, J. F, Wiseman, C, Xu, W, Yakushev, E, Yu, C. -H, Yumatov, V, Zhitnikov, I, Zhu, B. X
• Format: Journal Article
• Language: English
• Published: 26-03-2019
• Subjects: Physics - High Energy Physics - Experiment; Physics - Instrumentation and Detectors; Physics - Nuclear Experiment
• DOI: 10.48550/arxiv.1812.01090

Phys. Rev. D 99, 072004 (2019) The Majorana Demonstrator is an ultra low-background experiment searching for
neutrinoless double-beta decay in $^{76}$Ge. The heavily shielded array of
germanium detectors, placed nearly a mile underground at the Sanford
Underground Research Facility in Lead, South Dakota, also allows searches for
new exotic physics. We present the first limits for tri-nucleon decay-specific
modes and invisible decay modes for Ge isotopes. We find a half-life limit of
$4.9 \times 10^{25}$ yr for the decay $^{76}{\rm Ge(ppn)} \to {}^{73}{\rm Zn}\
e^+\pi^+$ and $4.7\times10^{25}$ yr for the decay $^{76}{\rm Ge(ppp)} \to
^{73}{\rm Cu}\ e^+\pi^+\pi^+$. The half-life limit for the invisible tri-proton
decay mode of $^{76}$Ge was found to be $7.5\times10^{24}$ yr.