Measurement of the two neutrino double beta decay half-life of Zr-96 with the NEMO-3 detector

Abstract

Using 9.4 g of 96Zr isotope and 1221 days of data from the NEMO-3 detector corresponding to 0.031 kg y, the obtained 2 ν β β decay half-life measurement is T 1 / 2 2 ν = [ 2.35 ± 0.14 ( stat ) ± 0.16 ( syst ) ] × 10 19 yr . Different characteristics of the final state electrons have been studied, such as the energy sum, individual electron energy, and angular distribution. The 2 ν nuclear matrix element is extracted using the measured 2 ν β β half-life and is M 2 ν = 0.049 ± 0.002 . Constraints on 0 ν β β decay have also been set.