Abstract
We present the first result of the KamLAND-Zen experiment, measurement of 136Xe doublebeta decay. In an exposure of 77.6 days with 129 kg of 136Xe, two-neutrino double-beta decay half-life is measured precisely to be T2ν1/2 = 2:38±0:02(stat)±0:14(syst)×1021 yr. This value is consistent with the measurement by EXO-200 and significantly below the lower limit obtained by previous experiment. For the neutrinoless double-beta decay half-life, improved lower limit is set to T0ν1/2 > 5.7 × 1024 yr at 90% C.L. and corresponding upper limit of the effective neutrino mass is ranged to 0.3-0.6 eV depending on the adopted nuclear matrix elements.
Original language | English |
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Pages | 359-364 |
Number of pages | 6 |
Publication status | Published - 2012 |
Event | 47th Rencontres de Moriond on Electroweak Interactions and Unified Theories, EW 2012 - La Thuile, Italy Duration: 2012 Mar 3 → 2012 Mar 10 |
Conference
Conference | 47th Rencontres de Moriond on Electroweak Interactions and Unified Theories, EW 2012 |
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Country/Territory | Italy |
City | La Thuile |
Period | 12/3/3 → 12/3/10 |
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Atomic and Molecular Physics, and Optics