Effects for atmospheric neutrino experiments from electron neutrino oscillations

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 pi/4. In the Exact Parity Symmetric Model, both the muon and electron neutrinos are expected to be maximally mixed with essentially sterile partners (nu(mu)' and nu(e)' respectively). We examine the impact of maximal nu(e)-nu(e)' oscillations on the atmospheric neutrino experiments. We estimate that maximal nu(e)-nu(e)' oscillations will have effects on atmospheric neutrino data for \delta m(2)(nu(e)-nu(e)')\ > 7 x 10(-5) ev(2). For delta 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 degrees to those with zenith angles greater than 90 degrees should be greater than 1. (C) 1997 Elsevier Science B.V.