Tau Appearance from High-Energy Neutrino Interactions

TL;DR

This paper investigates how high-energy neutrino interactions produce tau neutrinos, significantly impacting detection capabilities in PeV and EeV energy ranges, and shows Earth-skimming experiments can detect cosmogenic neutrinos even without primary tau-neutrino flux.

Contribution

It is the first to analyze the impact of secondary tau neutrino fluxes from high-energy neutrino interactions on detection prospects.

Findings

Tau neutrino flux exceeds atmospheric background above 300 TeV.

Earth-skimming experiments can detect cosmogenic neutrinos without primary tau-neutrino flux.

Secondary tau neutrinos significantly influence neutrino telescope sensitivities.

Abstract

High-energy muon- and electron-neutrinos yield a non-negligible flux of tau neutrinos as they propagate through Earth. In this letter, we address the impact of this additional component in the PeV and EeV energy regimes for the first time. This contribution is predicted to be significantly larger than the atmospheric background above 300 TeV, and alters current and future neutrino telescopes' capabilities to discover a cosmic tau-neutrino flux. Further we demonstrate that Earthskimming neutrino experiments, designed to observe tau neutrinos, will be sensitive to cosmogenic neutrinos even in extreme scenarios without a primary tau-neutrino component.