Large Reactor Neutrino Mixing Angle Supports a Fourier Approach to the Mass Hierarchy Problem

Daine Danielson

Abstract

The neutrino mass hierarchy problem presents an important open question in particle physics. Two alternate hypotheses describe the mass-ordering of the three neutrino masses: the ‘normal’ hierarchy, m1 < m2 < m3; and the ‘inverted’ hierarchy, m3 < m1 < m2. We review a method for measuring the neutrino mass hierarchy using Fourier analysis of reactor electron antineutrino disappearance oscillations. We present theoretical curves describing the expected response of a 10 kt scintillatordoped water-based electron antineutrino detector positioned 50 km away from a 8 GWth nuclear reactor, using updated neutrino oscillation parameters; the experimental consensus around a ‘large’ reactor neutrino mixing angle, θ13 ≈ 0.16 > 0, supports the viability of our approach. We show a strong mass hierarchy dependance in the shape of the Fourier power spectrum, robust under uncertainties on the absolute values of the hierarchy parameters |∆m2 ij |.

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