Determining neutrino mass hierarchy by precision measurements in electron and muon neutrino disappearance experiments

Recently a new method for determining the neutrino mass hierarchy by comparing the effective values of the atmospheric Δm2 measured in the electron neutrino disappearance channel, Δm2(ee), with the one measured in the muon neutrino disappearance channel, Δm2(μμ), was proposed. If Δm2(ee) is larger (smaller) than Δm2(μμ) the hierarchy is of the normal (inverted) type. We reexamine this proposition in the light of two very high precision measurements: Δm2(μμ) that may be accomplished by the phase II of the Tokai-to-Kamioka (T2K) experiment, for example, and Δm2(ee) that can be envisaged using the novel Moessbauer enhanced resonant νe absorption technique. Under optimistic assumptions for the systematic uncertainties of both measurements, we estimate the parameter region of (θ13, δ) in which the mass hierarchy can be determined. If θ13 is relatively large, sin22θ13(greater-or-similar sign)0.05, and both of Δm2(ee) and Δm2(μμ) can be measured with the precision of ∼0.5% it is possible to determine the neutrino mass hierarchy at >95% CL for 0.3π(less-or-similar sign)δ(less-or-similar sign)1.7π for the current best fit values of all the other oscillation parameters