Ultra-High-Energy Tau Neutrino Cross Sections with GRAND and POEMMA

TL;DR

Next-generation neutrino experiments like GRAND and POEMMA aim to measure ultra-high-energy tau neutrino cross sections by analyzing Earth absorption effects, providing insights into neutrino properties at energies around 10^9 GeV.

Contribution

This paper demonstrates that with approximately 100 detected events, the tau neutrino-nucleon cross section can be measured with about 20% precision using upcoming experiments.

Findings

Tau neutrino cross section can be extracted with ~20% accuracy.

Earth absorption effects enable neutrino property measurements at extreme energies.

Next-generation detectors will significantly advance high-energy neutrino physics.

Abstract

Next generation neutrino experiments will push the limits in our understanding of astroparticle physics in the neutrino sector to energies orders of magnitude higher than the current state-of-the-art high-energy neutrino experiment, IceCube. These experiments will use neutrinos to tell us about the most extreme environments in the universe, while simultaneously leveraging these extreme environments as probes of neutrino properties at the highest energies accessible in the foreseeable future: $E\sim10^9$ GeV. At these energies neutrinos are readily absorbed in the Earth. Assuming an isotropic distribution, by looking at how the flux varies as a function of angle through the Earth, we show that it is possible to extract the $\nu_\tau$-$N$ cross section with precision at the $\sim20\%$ level ($1\sigma$ assuming Wilks' theorem) given $N_{\rm events}\sim100$ events.