Limits on different Majoron decay modes of $^{100}$Mo and $^{82}$Se for neutrinoless double beta decays in the NEMO-3 experiment

TL;DR

This paper reports new experimental limits on Majoron-emitting neutrinoless double beta decay modes for isotopes $^{100}$Mo and $^{82}$Se, constraining neutrino-Majoron coupling constants using the NEMO-3 detector data.

Contribution

The study provides the first limits on Majoron decay modes for these isotopes and improves constraints on neutrino-Majoron couplings in neutrinoless double beta decay.

Findings

New half-life limits for Majoron decay modes: $^{100}$Mo > 2.7×10^{22} years, $^{82}$Se > 1.5×10^{22} years.

Bounds on the neutrino-Majoron coupling constant: <g_{ee}> < (0.4-1.9)×10^{-4} and < (0.66-1.7)×10^{-4}.

Enhanced constraints on Majoron emission in neutrinoless double beta decay.

Abstract

The NEMO-3 tracking detector is located in the Fr\'ejus Underground Laboratory. It was designed to study double beta decay in a number of different isotopes. Presented here are the experimental half-life limits on the double beta decay process for the isotopes $^{100}$Mo and $^{82}$Se for different Majoron emission modes and limits on the effective neutrino-Majoron coupling constants. In particular, new limits on "ordinary" Majoron (spectral index 1) decay of $^{100}$Mo ($T_{1/2} > 2.7\cdot10^{22}$ y) and $^{82}$Se ($T_{1/2} > 1.5\cdot10^{22}$ y) have been obtained. Corresponding bounds on the Majoron-neutrino coupling constant are $<g_{ee} > < (0.4-1.9) \cdot 10^{-4}$ and $< (0.66-1.7) \cdot 10^{-4}$.