Limit on the decayD0→eμ∓

Abstract

We have searched for the lepton-flavor-violating decay $D^0$→$e^{\pm }$ ${\mu }^{\mp }$ in 204 ${\mathrm{pb}}^{\mathrm{-}1}$ of $e^{+}$ $e^{\mathrm{-}}$ annihilation data at $E_{\mathrm{c}.\mathrm{m}.\mathrm{}=29\mathrm{}}$ GeV from the Mark II detector. No candidates were found; we estimate an upper limit on the cross section times branching ratio of σ($e^{+}$ $e^{\mathrm{-}}$→$D^0$,D${¯}^0$; inclusive)B($D^0$→$e^{\pm }$ ${\mu }^{\mp }$)$D^0$→$e^{\pm }$ ${\mu }^{\mp }$)${10}^{-3}$. AE.