# Constraints on Neutrino Lifetime from the Sudbury Neutrino Observatory

## TL;DR

This paper uses data from the Sudbury Neutrino Observatory to set new lower bounds on the lifetime of neutrino mass state bc2, constraining possible neutrino decay models through energy-dependent survival probability analysis.

## Contribution

It provides the first comprehensive fit of a neutrino decay model to all three phases of SNO bc8B solar neutrino data, improving constraints on neutrino lifetime.

## Key findings

- Neutrino lifetime bc2 > 8.08 ^{-5} s/eV at 90% confidence
- Combined analysis yields bc2 > 1.04 ^{-3} s/eV at 99% confidence
- Results place stringent limits on neutrino decay scenarios.

## Abstract

The long baseline between the Earth and the Sun makes solar neutrinos an excellent test beam for exploring possible neutrino decay. The signature of such decay would be an energy-dependent distortion of the traditional survival probability which can be fit for using well-developed and high precision analysis methods. Here a model including neutrino decay is fit to all three phases of $^8$B solar neutrino data taken by the Sudbury Neutrino Observatory. This fit constrains the lifetime of neutrino mass state $\nu_2$ to be ${>8.08\times10^{-5}}$ s/eV at $90\%$ confidence. An analysis combining this SNO result with those from other solar neutrino experiments results in a combined limit for the lifetime of mass state $\nu_2$ of ${>1.04\times10^{-3}}$ s/eV at $99\%$ confidence.