Light curves of BSM-induced neutrino echoes in the optically-thin limit

TL;DR

This paper derives analytic formulas for neutrino light curves affected by beyond Standard Model interactions, aiding the study of neutrino scattering with cosmic backgrounds or dark matter.

Contribution

It introduces general analytic formulas for neutrino echo light curves under BSM interactions, applicable to various scattering scenarios.

Findings

Formulas enable constraints on neutrino-neutrino and neutrino-DM scattering.

Applicable to astrophysical neutrino observations for probing new physics.

Provides a framework for analyzing neutrino time-delay signatures.

Abstract

High-energy neutrinos from astrophysical transients serve as a probe of neutrino physics beyond the Standard Model. In particular, nonstandard interaction of neutrinos with the cosmic neutrino background or dark matter (DM) may have imprints on not only their spectra but also the arrival and time-delay distributions. Assuming that the interaction occurs at most once during the neutrino propagation, we provide general analytic formulas for light curves of the neutrino echoes induced by BSM. The formulas can be used for constraining neutrino-neutrino scattering, neutrino-DM scattering, and other scattering processes experienced by relativistic particles.