Visible Neutrino Decays and the Impact of the Daughter-Neutrino Mass

TL;DR

This paper calculates neutrino decay widths considering nonzero daughter masses, exploring how different decay interactions and daughter masses influence experimental signatures, especially at JUNO.

Contribution

It provides detailed decay width calculations for Dirac neutrinos with massive daughters and analyzes their impact on experimental observations.

Findings

Decay daughters' mass significantly affects decay signatures.

Right-chiral neutrino decay channels can alter experimental signals.

Comparison of visible and invisible decays at JUNO shows measurable differences.

Abstract

We compute the differential decay width of two- and three-body neutrino decays, assuming neutrinos are Dirac fermions and allowing for the possibility that the decay-daughters have nonzero masses. We examine different hypotheses for the interaction that mediates neutrino decay and concentrate on identifying circumstances where the decay-daughters can significantly impact the neutrino-decay signature at different experiments. We are especially interested in decay daughters produced by right-chiral neutrino fields, when the mass of the daughter plays a decisive role. As a concrete example, we compare the effects of visible and invisible antineutrino decays at the JUNO experimental setup.