Search for the rare semi-leptonic decay $J/psito D^{-}e^{+} u_{e}+c.c.$

Using $10.1times10^{9}$ $J/psi$ events produced by the Beijing Electron Positron Collider (BEPCII) at a center-of-mass energy $sqrt{s}=3.097~rm{GeV}$ and collected with the BESIII detector, we present a search for the rare semi-leptonic decay $J/psito D^{-}e^{+} u_{e}+c.c.$. No excess of signal above background is observed, and an upper limit on the branching fraction $mathcal{B}(J/psito D^{-}e^{+} u_{e}+c.c.)<7.1times10^{-8}$ is obtained at $90%$ confidence level. This is an improvement of more than two orders of magnitude over the previous best limit.