| Autor: |
Alvis, SI, Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Basu, V, Bertrand, FE, Bos, B, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Clark, M, Cuesta, C, Detwiler, JA, Efremenko, Yu, Ejiri, H, Elliott, SR, Gilliss, T, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Hegedus, RJ, Hehn, L, Henning, R, Aguilar, D Hervas, Hoppe, EW, Howe, MA, Kidd, MF, Konovalov, SI, Kouzes, RT, Lopez, AM, Martin, RD, Massarczyk, R, Meijer, SJ, Mertens, S, Myslik, J, Othman, G, Pettus, W, Piliounis, A, Poon, AWP, Radford, DC, Rager, J, Reine, AL, Rielage, K, Ruof, NW, Shanks, B, Shirchenko, M, Tedeschi, D, Varner, RL, Vasilyev, S, White, BR, Wilkerson, JF, Wiseman, C, Xu, W, Yakushev, E, Yu, C-H, Yumatov, V, Zhitnikov, I, Zhu, BX |
| Rok vydání: |
2019 |
| Předmět: |
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| Zdroj: |
Physical Review C, vol 100, iss 2 |
| Popis: |
The Majorana Collaboration is operating an array of high-purity Ge detectors to search for the neutrinoless double-β decay of Ge76. The Majorana Demonstrator consists of 44.1 kg of Ge detectors (29.7 kg enriched to 88% in Ge76) split between two modules constructed from ultraclean materials. Both modules are contained in a low-background shield at the Sanford Underground Research Facility in Lead, South Dakota. We present updated results on the search for neutrinoless double-β decay in Ge76 with 26.0±0.5 kg yr of enriched exposure. With the Demonstrator's energy resolution of 2.53 keV FWHM at Qββ, which is the best among all neutrinoless double-β decay experiments, we observe one event in the region of interest with 0.65 events expected from the estimated background, resulting in a lower limit on the Ge76 neutrinoless double-β decay half-life of 2.7×1025 yr [90% confidence level (CL)] with a median sensitivity of 4.8×1025 yr (90% CL). Depending on the matrix elements used, a 90% CL upper limit on the effective Majorana neutrino mass in the range of 200-433 meV is obtained. The measured background in the configurations with full shielding and optimized grounding is 11.9±2.0 counts/(FWHM t yr). |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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