Tau Appearance from High-Energy Neutrino Interactions

Area of Science:

• Astroparticle Physics
• High-Energy Neutrino Astronomy
• Cosmic Ray Physics

Background:

• Muon and electron neutrinos traversing Earth generate tau neutrinos.
• This secondary tau neutrino flux is significant at PeV and EeV energies.
• Understanding this flux is crucial for interpreting neutrino telescope data.

Purpose of the Study:

• To quantify the impact of Earth-generated tau neutrinos on PeV and EeV neutrino detection.
• To assess how this flux affects the capabilities of current and future neutrino telescopes.
• To explore the sensitivity of Earth-skimming experiments to cosmogenic neutrinos.

Main Methods:

• Simulations and theoretical calculations of neutrino propagation through Earth.
• Analysis of expected tau neutrino fluxes in the PeV and EeV energy ranges.
• Modeling the response of neutrino telescopes and Earth-skimming detectors.

Main Results:

• The tau neutrino contribution exceeds the atmospheric background above 300 TeV.
• This flux significantly alters the expected signal for cosmic tau neutrino searches.
• Earth-skimming experiments show sensitivity to cosmogenic neutrinos, even without primary tau neutrinos.

Conclusions:

• The secondary tau neutrino flux is a critical factor in high-energy neutrino astronomy.
• Future neutrino telescopes must account for this component for accurate cosmic tau neutrino discovery.
• Earth-skimming experiments offer a unique window into cosmogenic neutrinos.