Constraints on Neutrino Self-Interactions from IceCube Observation of NGC 1068

TL;DR

This paper uses IceCube observations of NGC 1068 to set new limits on neutrino self-interactions mediated by scalar particles, especially for flavor-specific tau neutrino interactions with low-mass mediators.

Contribution

It provides novel constraints on neutrino self-interactions using astrophysical neutrino data from a steady extragalactic source.

Findings

Constraints on tau neutrino self-interactions are comparable to diffuse flux bounds.

Constraints on flavor-universal interactions are weaker than existing bounds.

Limits are set for mediator masses between 1-10 MeV.

Abstract

The active galaxy NGC 1068 was recently identified by the IceCube neutrino observatory as the first known steady-state, extragalactic neutrino point source, associated with about 79 events over ten years. We use the IceCube data to place limits on possible neutrino self-interactions mediated by scalar particles with mass between 1 - 10 MeV. We find that constraints on flavor-specific $\nu_{\tau}$ self-interactions with low mediator masses are comparable to constraints derived from the diffuse high-energy neutrino flux at low energies, while constraints on flavor-universal self-interactions are less restrictive than current bounds.