UC Irvine

Using a sample of 2.25 × 108 J/ψ events collected with the BESIII detector at the BEPCII collider, we search for the J/ψ semileptonic weak decay J/ψ → D-s e+νe+ c.c. with a much higher sensitivity than previous searches. We also perform the first search for J/ψ → D∗-s e+νe + c.c. No significant excess of a signal above background is observed in either channel. At the 90% confidence level, the upper limits are determined to be B(J/ψ → D-s e+νe + c.c. )< 1.3 × 10-6 and B(J=ψ → D∗-s e+νe + c.c. ) < 1.8 × 10-6, respectively. Both are consistent with Standard Model predictions.