# Radio-detection of neutrino-induced air showers: the influence of topography

## TL;DR

This paper investigates how mountainous terrain can significantly enhance the detection efficiency of radio signals from neutrino-induced air showers, emphasizing the importance of topography in designing neutrino observatories.

## Contribution

It demonstrates that even slight inclinations in terrain can triple detection efficiency, highlighting topography as a crucial factor in neutrino detection experiments.

## Key findings

- Mountainous terrain increases detection efficiency by up to three times.
- Topography significantly influences the probability of detecting neutrino-induced air showers.
- Flat sites may underestimate the true detection potential in mountainous regions.

## Abstract

Neutrinos of astrophysical origin could be detected through the electromagnetic radiation of the particle showers induced in the atmosphere by their interaction in the Earth. This applies in particular for tau neutrinos of energies $E>10^{16}$eV following Earth-skimming trajectories. The $\sim1^{\circ}$ beaming of the radio emission in the forward direction however implies that the radio signal will likely fly above a detector deployed over a flat site and would therefore not be detected. We study here how a non-flat detector topography can improve the detection probability of these neutrino-induced air showers. We do this by computing with three distinct tools the neutrino detection efficiency for a radio array deployed over a toy-model mountainous terrain, also taking into account experimental and topographic constraints. We show in particular that ground topographies inclined by few degrees only induce detection efficiencies typically three times larger than those obtained for flat areas for favorable trajectories. We conclude that the topography of the area where the detector is deployed will be a key factor for an experiment like GRAND.