Strong Supernova 1987A Constraints on Bosons Decaying to Neutrinos

TL;DR

This paper uses observations from Supernova 1987A to set new constraints on bosons that decay into neutrinos, significantly limiting their possible interactions and masses based on the absence of high-energy neutrino signals.

Contribution

It introduces a novel method to constrain bosons decaying into neutrinos using supernova data, improving bounds on their coupling and mass range.

Findings

Less than 1% of supernova energy emitted as high-energy neutrinos from boson decays.

Established the strongest limits on Majoron-neutrino coupling for masses between 100 eV and 100 MeV.

Method can be applied to other feebly interacting particles.

Abstract

Majoron-like bosons would emerge from a supernova (SN) core by neutrino coalescence of the form $\nu\nu\to\phi$ and $\bar\nu\bar\nu\to\phi$ with 100 MeV-range energies. Subsequent decays to (anti)neutrinos of all flavors provide a flux component with energies much larger than the usual flux from the "neutrino sphere." The absence of 100 MeV-range events in the Kamiokande-II and Irvine-Michigan-Brookhaven signal of SN 1987A implies that less than 1% of the total energy was thus emitted and provides the strongest constraint on the Majoron-neutrino coupling of $g\lesssim 10^{-9}\,{\rm MeV}/m_\phi$ for $100~{\rm eV}\lesssim m_\phi\lesssim 100~{\rm MeV}$. It is straightforward to extend our new argument to other hypothetical feebly interacting particles.