Neutrino mass hierarchy and octant determination with atmospheric neutrinos

Abstract

The recent discovery by the Daya-Bay and RENO experiments, that θ₁₃ is nonzero and relatively large, significantly impacts existing experiments and the planning of future facilities. In many scenarios, the nonzero value of θ13 implies that θ₂₃ is likely to be different from π/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 θ₂₃. We show that a 50 kT magnetized liquid argon neutrino detector can ascertain the mass hierarchy with a significance larger than 4σ with moderate exposure times and the octant at the level of 2–3σ with greater exposure.