Study of $\eta \to {\pi }^{+}{\pi }^{-}{l}^{+}{l}^{-}$

BESIII Collaboration, M. Ablikim, M. N. Achasov +639

Using a sample of $(10087\pm 44)\times 10^6$ $J/\psi$ events accumulated with the BESIII detector, we analyze the decays $\eta \to {\pi }^{+}{\pi }^{-}{l}^{+}{l}^{-}$ ($l=e$ or $\mu$) via the process $J/ψ…