Observable features in (ultra)high energy neutrinos due to active-sterile secret interactions

TL;DR

This paper investigates how secret interactions between active and sterile neutrinos mediated by a pseudoscalar affect high-energy neutrino fluxes, revealing new parameter space regions and potential observable effects in current and future experiments.

Contribution

It extends previous models to a 3 active plus 1 sterile neutrino framework, exploring phenomenological implications of secret interactions on neutrino fluxes and flavor ratios.

Findings

Active fluxes can show measurable depletion in future experiments.

Effects on astrophysical fluxes may already be probed by IceCube.

Energy-dependent flavor ratio features are identified.

Abstract

We consider the effects of active-sterile secret neutrino interactions, mediated by a new pseudoscalar particle, on high- and ultra high-energy neutrino fluxes. In particular, we focus on the case of 3 active and 1 sterile neutrino coupled by a flavor dependent interaction, extending the case of 1 active and 1 sterile neutrino we have recently examined. We find that, depending on the kind of interaction of sterile neutrino with the active sector, new regions of the parameter space for secret interactions are now allowed leading to interesting phenomenological implications on two benchmark fluxes we consider, namely an astrophysical power law flux, in the range below 100 PeV, and a cosmogenic flux, in the Ultrahigh energy range. First of all, the final active fluxes can present a measurable depletion observable in future experiments. Especially, in the case of only tau neutrino interacting, we find that the effects on the astrophysical power law flux can be so large to be already probed by the IceCube experiment. Moreover, we find intriguing features in the energy dependence of the flavor ratio.