Neutrino Decay and Atmospheric Neutrinos

TL;DR

This paper explores neutrino decay as an alternative explanation for atmospheric neutrino data, proposing a model involving decay to sterile neutrinos and Majorons that fits observations well and can be distinguished from oscillation scenarios by future experiments.

Contribution

It introduces a decay-based model for atmospheric neutrino observations, highlighting the role of small mass differences and sterile neutrino decay, and discusses experimental distinctions.

Findings

Decay model fits atmospheric neutrino data well

Small mass difference (<10^{-4} eV^2) is crucial

Future experiments can distinguish decay from oscillation

Abstract

We reconsider neutrino decay as an explanation for atmospheric neutrino observations. We show that if the mass-difference relevant to the two mixed states \nu_\mu and \nu_\tau is very small (< 10^{-4} eV^2), then a very good fit to the observations can be obtained with decay of a component of \nu_\mu to a sterile neutrino and a Majoron. We discuss how the K2K and MINOS long-baseline experiments can distinguish the decay and oscillation scenarios.