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 $\ddot{I}€/4$. In the Exact Parity Symmetric Model, both the muon and electron neutrinos are expected to be maximally mixed with essentially sterile partners ($\hat{I}{½}_{\hat{I}}^{\prime }¼$ and $\hat{I}{½}_e^{\prime }$ respectively). We examine the impact of maximal $\hat{I}{½}_e-\hat{I}{½}_e^{\prime }$ oscillations on the atmospheric neutrino experiments. We estimate that maximal $\hat{I}{½}_e-\hat{I}{½}_e^{\prime }$ oscillations will have effects on atmospheric neutrino data for $|\hat{I}´m^2(\hat{I}{½}_e-\hat{I}{½}_e^{\prime })|>7\times 10^{-5}e{V}^2$. For $\hat{I}´m^2$ 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 $90\hat{A}°$ to those with zenith angles greater than $90\hat{A}°$ should be greater than 1.

11 pages, LaTeX, no figures