Search for baryon and lepton number violating decays

We search for the baryon and lepton number violating charm decays, $D\to p\mathrm{\ell }$, where $D$ is either a $D^0$ or a ${\bar{D}}^0$ and $\mathrm{\ell }$ is a muon or an electron, using a data sample of $921{\mathrm{f}\mathrm{b}}^{-1}$ collected by the Belle detector at the KEKB asymmetric energy $e^{+}{e}^{-}$ collider. In the absence of significant signals, we set upper limits on the branching fractions in the range $(5-8)\times {10}^{-7}$ at a 90% confidence level, depending on the decay mode.