Results from NEMO 3

TL;DR

The NEMO 3 experiment has measured double beta decay half-lives for several isotopes, providing important data for neutrino physics, but found no evidence for neutrinoless decay, setting limits on neutrino mass.

Contribution

This paper reports new precision measurements of two-neutrino double beta decay half-lives for isotopes 96Zr, 48Ca, and 150Nd, and sets limits on neutrinoless decay.

Findings

Measured half-lives for 96Zr, 48Ca, and 150Nd.

No evidence found for neutrinoless double beta decay.

Set lower limits on half-life and upper limits on neutrino mass.

Abstract

The NEMO 3 experiment is located in the Modane Underground Laboratory and has been taking data since 2003 with seven isotopes. It is searching for the double beta decay process with two or zero neutrinos emitted in the final state. Precision measurements of the half-life of the isotopes due to two neutrino double beta decay have been performed and new results for 96Zr, 48Ca and 150Nd are presented here. Measurements of this process are important for reducing the uncertainties on the nuclear matrix elements. No evidence for zero neutrino double beta decay has been found and a 90% Confidence Level lower limit on the half-life of this process is derived. From this an upper limit can be set on the effective Majorana neutrino mass using the most recent nuclear matrix elements calculations.