Effects for atmospheric neutrino experiments from electron neutrino oscillations

Abstract

The minimal interpretation of the atmospheric neutrino data suggests that the muon neutrino oscillates into another species with a mixing angle close to the maximal $π/4$. In the Exact Parity Symmetric Model, both the muon and electron neutrinos are expected to be maximally mixed with essentially sterile partners ($ν'_μ$ and $ν'_e$ respectively). We examine the impact of maximal $ν_e - ν'_e$ oscillations on the atmospheric neutrino experiments. We estimate that maximal $ν_e - ν'_e$ oscillations will have effects on atmospheric neutrino data for $|δm^2 (ν_e - ν_e')| > 7 \times 10^{-5} eV^2$. For $δm^2$ in this range, a slight but distinctive rise in the ratio of muon-like to electron-like events is predicted for the low-energy sample. Furthermore, the ratio of low-energy electron-like events with zenith angles less than $90°$ to those with zenith angles greater than $90°$ should be greater than 1.