Neutrino mass hierarchy and octant determination with atmospheric neutrinos

TL;DR

This paper demonstrates that a large magnetized liquid argon detector can determine the neutrino mass hierarchy and the octant of heta_{23} using atmospheric neutrinos, leveraging matter effects influenced by recent heta_{13} measurements.

Contribution

It shows the potential of a 50 kT detector to determine neutrino properties with significant confidence levels, considering recent experimental findings.

Findings

Mass hierarchy can be identified with >4 sigma significance.

Octant of heta_{23} can be determined at 2-3 sigma significance.

Detector sensitivity depends on exposure time and matter effects.

Abstract

The recent discovery by the Daya-Bay and RENO experiments, that \theta_{13} is nonzero and relatively large, significantly impacts existing experiments and the planning of future facilities. In many scenarios, the nonzero value of \theta_{13} implies that \theta_{23} is likely to be different from \pi/4. Additionally, large detectors will be sensitive to matter effects on the oscillations of atmospheric neutrinos, making it possible to determine the neutrino mass hierarchy and the octant of \theta_{23}. We show that a 50 kT magnetized liquid argon neutrino detector can ascertain the mass hierarchy with a significance larger than 4 sigma with moderate exposure times, and the octant at the level of 2-3 sigma with greater exposure.