The search for $D^0\to{}e^{\pm}\mu^{\mp}$

An overview is presented of a method to search for $D^0\to{}e^{\pm}\mu^{\mp}$ with LHCb data. In order to reduce combinatorial backgrounds, tagged $D^0$ candidates from the decay $D^{\ast+}\to{}D^0\pi^+$ are used. This measurement is performed with respect to $\mathcal{B}\left(D^0\to{}\pi^+\pi^-\right)$, which cancels uncertainties in the luminosity and $D^{\ast+}$ production cross-section. It is estimated that using $3\,\mathrm{fb}^{-1}$ of LHCb data an upper limit can be attained of $\mathcal{O}\left(10^{-7}\right)$ at a $90\%$ confidence level.