Search for the rare decays $J/\psi \to D_s^-\rho^+$ and $J/\psi \to   \overline{D}{}^0\overline{K}{}^{\ast0}$
  A search for the rare decays of $J/\psi \to D_s^-\rho^+ + c.c.$ and $J/\psi \to \overline{D}{}^0\overline{K}{}^{\ast0} + c.c.$ is performed with a data sample of 225.3 million $J/\psi$ events collected with the BESIII detector. No evident signal is observed. Upper limits on the branching fractions are determined to be $\mathcal{B}(J/\psi \to D_s^-\rho^+ + c.c.) < 1.3 \times 10^{-5}$ and $\mathcal{B}(J/\psi \to \overline{D}{}^0\overline{K}{}^{\ast0} + c.c.) < 2.5 \times 10^{-6}$ at the $90\%$ confidence level. 
BESIII Collaboration: M. Ablikim, M. N. Achasov, X. C. Ai, O.   Albayrak, M. Albrecht, D. J. Ambrose, F. F. An, Q. An, J. Z....
hep-ex