Search for the weak decays J/ψ → D{_s^{(*)⁻} e⁺ ν_e + c.c.

Using a sample of 2.25 x 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⁺ν(e) + c.c with a much higher sensitivity than previous searches. We also perform the first search for J/ψ → D(s)^(*⁻) e⁺ν(e) + 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⁺ν(e) + c.c.) < 1.3 x 10⁻⁶ and ℬ(J/ψ → D(s)^(*⁻) e⁺ν(e) + c.c.) < 1.8 X 10⁻⁶, respectively. Both are consistent with Standard Model predictions.