Comment on the possible electron neutrino excess in the Super-Kamiokande atmospheric neutrino experiment

Abstract

We investigate the implications of a possible excess of the electron neutrino events in the Super-Kamiokande atmospheric neutrino experiment. The excess, if real, leads to constraints on the $\nu_\mu \leftrightarrow \nu_e$, $\nu_\mu \leftrightarrow \nu_\tau$ and $\nu_e \leftrightarrow \nu_\tau$ oscillation parameters. Specifically, the excess impies that $\nu_e - \nu_\mu$ and $\nu_\mu - \nu_\tau$ mixings are large and $\nu_e - \nu_\tau$ mixing is small. We show that the electron neutrino excess favors the large mixing angle MSW solution of the solar neutrino problem.