## Abstract

Using data from the NEMO-3 experiment, we have measured the two-neutrino double beta decay (2 νββ) half-life of ^{82}Se as T1/22ν=[9.39±0.17(stat)±0.58(syst)]×1019 y under the single-state dominance hypothesis for this nuclear transition. The corresponding nuclear matrix element is |M^{2}
^{ν}| = 0.0498 ± 0.0016. In addition, a search for neutrinoless double beta decay (0 νββ) using 0.93 kg of ^{82}Se observed for a total of 5.25 y has been conducted and no evidence for a signal has been found. The resulting half-life limit of T1/20ν>2.5×1023y(90%C.L.) for the light neutrino exchange mechanism leads to a constraint on the effective Majorana neutrino mass of ⟨mν⟩<(1.2-3.0)eV, where the range reflects 0 νββ nuclear matrix element values from different calculations. Furthermore, constraints on lepton number violating parameters for other 0 νββ mechanisms, such as right-handed currents, majoron emission and R-parity violating supersymmetry modes have been set.

Original language | English |
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Article number | 821 |

Journal | European Physical Journal C |

Volume | 78 |

Issue number | 10 |

Early online date | 11 Oct 2018 |

DOIs | |

Publication status | Published - 11 Oct 2018 |