Search for the FCNC charmonium decay $\textit{J/ψ → D}$

Based on a data sample of (10087 ± 44) × 10 $\textit{J}$/$\textit{ψ}$ events taken with the BESIII detector, we search for the flavor-changing neutral current charmonium decay $\textit{J}$/$\textit{ψ}$ → $\textit{D}$ $\textit{μ}$ $\textit{μ}$ + c.c. . No significant signal above the background is observed, and the upper limit on its branching fraction is set to be ℬ($\textit{J}$/$\textit{ψ}$ → $\textit{D}$ $\textit{μ}$ $\textit{μ}$ + c.c.) < 1.1 × 10 at the 90% confidence level. This marks the first search for a flavor-changing neutral current charmonium decay involving muons in the final state.