$(B+L)$-conserving Nucleon Decays in Supersymmetric Models

The presence of the $(B+L)$-conserving decay modes $n \to K^+ e^-,$ $n \to K^+ \mu^-,$ $p \to K^+ e^- \pi^+$ and $p \to K^+ \mu^- \pi^+$ is shown to be a characteristic feature of a class of models with explicit breaking of $R$-parity. These modes dominate over the $(B-L)$-conserving ones in certain regions of the parameter space; the impact of this scenario for nucleon decay search at the Super-Kamiokande is discussed.