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

TL;DR

This paper reports a precise measurement of the two-neutrino double beta decay half-life of Zr-96 using the NEMO-3 detector, analyzing electron characteristics and setting constraints on neutrinoless decay.

Contribution

First measurement of Zr-96's 2vbb decay half-life with detailed electron analysis and nuclear matrix element extraction.

Findings

Half-life of Zr-96 2vbb decay: (2.35 +/- 0.14(stat) +/- 0.16(syst)) x 10^19 yr

Extracted nuclear matrix element: 0.049 +/- 0.002

Constraints on neutrinoless double beta decay established

Abstract

Using 9.4 g of Zr-96 and 1221 days of data from the NEMO-3 detector corresponding to 0.031 kg yr, the obtained 2vbb decay half-life measurement is [2.35 +/- 0.14(stat) +/- 0.16(syst)] x 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 2v nuclear matrix element is extracted using the measured 2vbb half-life and is 0.049 +/- 0.002. Constraints on 0vbb decay have also been set.