Search for Trilepton Nucleon Decay via $p \rightarrow e^+ \nu \nu$ and   $p \rightarrow \mu^+ \nu \nu$ in the Super-Kamiokande Experiment
  The trilepton nucleon decay modes $p \rightarrow e^+ \nu \nu$ and $p \rightarrow \mu^+ \nu \nu$ violate $|\Delta (B - L)|$ by two units. Using data from a 273.4 kiloton year exposure of Super-Kamiokande a search for these decays yields a fit consistent with no signal. Accordingly, lower limits on the partial lifetimes of $\tau_{p \rightarrow e^+ \nu \nu} > 1.7 \times 10^{32}$ years and $\tau_{p \rightarrow \mu^+ \nu \nu} > 2.2 \times 10^{32}$ years at a $90 \% $ confidence level are obtained. These limits can constrain Grand Unified Theories which allow for such processes. 
V. Takhistov, K. Abe, Y. Haga, Y. Hayato, M. Ikeda, K. Iyogi, J.   Kameda, Y. Kishimoto, M. Miura, S. Moriyama, M. Nakahata,...
hep-ex hep-ph