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.
Categories: hep-ex