# Neutrino Mass Ordering at DUNE: an Extra $\nu$-Bonus

## TL;DR

This paper explores how atmospheric neutrinos detected at DUNE's Liquid Argon detector can determine the neutrino mass ordering with high confidence, leveraging matter effects and charge-tagging.

## Contribution

It demonstrates that atmospheric neutrino data at DUNE can achieve a 4σ determination of neutrino mass ordering within ten years, highlighting the advantage of charge-tagging with Argon.

## Key findings

- Potential 4σ significance in mass ordering determination after ten years.
- Effective charge-tagging enhances the ability to distinguish neutrino types.
- Atmospheric neutrinos provide a valuable early data source before beam operation.

## Abstract

We study the possibility of extracting the neutrino mass ordering at the future Deep Underground Neutrino Experiment using atmospheric neutrinos, which will be available before the muon neutrino beam starts being perational. The large statistics of the atmospheric muon neutrino and antineutrino samples at the far detector, together with the baselines of thousands of kilometers that these atmospheric (anti)neutrinos travel, provide the ideal ingredients to extract the neutrino mass ordering via matter effects in the neutrino propagation through the Earth. Crucially, muon capture by Argon provides excellent charge-tagging, allowing to disentangle the neutrino and antineutrino signature. This is a critical extra benefit of having a Liquid Argon Time Projection Chamber as far detector, that could render a $4\sigma$ extraction of the mass ordering after ten years of exposure.