2018/06/14 by 3 Collaboration, Arnold, R., Augier, C. +96
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #Nuclear Experiment (nucl-ex)
paper · doi:10.48550/arxiv.1806.05553
Using data from the NEMO-3 experiment, we have measured the two-neutrino double beta decay (2νββ) half-life of 82Se 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 |M2ν| = 0.0498 ± 0.0016. In addition, a search for neutrinoless double beta decay (0νββ) using 0.93 kg of 82Se 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 × 1023 y (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 0νββ nuclear matrix element values from different calculations. Furthermore, constraints on lepton number violating parameters for other 0νββ mechanisms, such as right-handed currents, majoron emission and R-parity violating supersymmetry modes have been set.