Validating the performance of the Radio Neutrino Observatory in Greenland using cosmic-ray air showers

TL;DR

This study validates the RNO-G detector's ability to detect cosmic rays consistent with expectations, which is crucial for future neutrino detection at ultra-high energies.

Contribution

It provides the first validation of cosmic-ray detection capabilities of RNO-G, confirming detector performance and identifying areas for improvement.

Findings

Cosmic-ray detection matches expectations.

Signal shape agrees with simulations.

Reconstructed parameters align with predictions.

Abstract

The Radio Neutrino Observatory in Greenland (RNO-G) is currently under construction with the aim to detect neutrinos with energies beyond $\sim 10\,\mathrm{PeV}$. A critical part of early detector commissioning is the study of detector characteristics and potential backgrounds, for which cosmic rays play a crucial role. In this article, we report that the number of cosmic rays detected with RNO-G's shallow antennas is consistent with expectations. We further verified the agreement in the observed cosmic-ray signal shape with expectations from simulations after careful treatment of the detector systematics. Finally, we find that the reconstructed arrival direction, energy, and polarization of the cosmic-ray candidates agrees with expectations. Throughout this study, we identified detector shortcomings that are mitigated going forward. Overall, the analysis presented here is an essential first step towards validating the detector and high-fidelity neutrino detection with RNO-G in the future.