Using the NEMO-3 detector, 410.4 g of ¹¹⁶Cd with a total exposure of 1.65 kg• y and 932 g of ⁸²Se with a total exposure of 3.75 kg• y were used to measure the half-life of two-neutrino double beta decay (2[nu][beta][beta]) to the ground states of ¹¹⁶Sn and ⁸²Kr and to place a lower limit on the neutrinoless double becay decay (0[nu][beta][beta]) to the same ground states. Under the single-states dominance hypothesis, the 2[nu][beta][beta] half-lives are found to be T 1/2(¹¹⁶Cd) = (2.90 ± 0.03(stat) ± 0.15(syst)×10¹⁹ yr and T 1/2(⁸²Se) = [10.62±0.11(stat)±0.56(syst)]×10¹⁹ yr. 0[nu][beta][beta] is excluded to 90% confidence level at T 1/2 ≥ 1.12 × 10²³ yr for ¹¹⁶Cd and T 1/2 ≥ 3.90 × 10²³ yr for ⁸²Se. These half-lives correspond to effective Majorana neutrino masses of m ≤ (4.33 - 5.54) eV and m ≤ (2.28 - 2.82) eV, respectively, in the light Majorana exchange mechanism. / text
| Identifer | oai:union.ndltd.org:UTEXAS/oai:repositories.lib.utexas.edu:2152/24790 |
| Date | 24 June 2014 |
| Creators | Liptak, Zachary John |
| Source Sets | University of Texas |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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