The next galactic supernova can uncover mass and couplings of particles decaying to neutrinos

TL;DR

A galactic supernova could reveal properties of hypothetical particles like Majorons by detecting high-energy neutrinos from their decay, helping determine their mass and couplings.

Contribution

This study demonstrates for the first time that supernova neutrino observations can constrain the mass and couplings of particles decaying into neutrinos.

Findings

High-energy neutrinos from supernova decay signatures can be detected.

Measurements can determine particle mass and flavor-dependent couplings.

Results applicable to other feebly interacting particles.

Abstract

Many particles predicted by extensions of the Standard Model feature interactions with neutrinos, e.g., Majoron-like bosons $\phi$. If the mass of $\phi$ is larger than about 10 keV, they can be produced abundantly in the core of the next galactic core-collapse supernova through neutrino coalescence, and leave it with energies of around 100 MeV. Their subsequent decay to high-energy neutrinos and anti-neutrinos provides a distinctive signature at Earth. Ongoing and planned neutrino and dark matter experiments allow us to reconstruct the energy, flavor, and time of arrival of these high-energy neutrinos. For the first time, we show that these measurements can help pinpointing the mass of $\phi$ and its couplings to neutrinos of different flavor. Our results can be generalized in a straightforward manner to other hypothetical feebly interacting particles, like novel gauge bosons or heavy neutral leptons, that decay into neutrinos.