Search for the charged lepton flavor violating decay $J/psito etau$

A search for the charged lepton flavor violating decay $J/psito e^{pm}tau^{mp}$ with $tau^{mp} to pi^{mp}pi^0 u_{tau}$ is performed with about $10$ billion $J/ psi$ events collected with the BESIII detector at the BEPCII. No significant signal is observed, and an upper limit is set on the branching fraction $mathcal{B}(J/psito e^{pm}tau^{mp})<7.5times10^{-8}$ at the 90$%$ confidence level. This improves the previously published limit by two orders of magnitude.