Study of the electromagnetic transitions $J/\psi \to P{l}^{+}{l}^{-}$ and probe dark photon

Jinlin Fu, Hai-Bo Li, Xiaoshuai Qin +1

We study the electromagnetic Dalitz decay modes of $J/\psi \to P{l}^{+}{l}^{-}$ ($P={\pi }^0$, $\eta$ or ${\eta }^{\prime }$). In these decays, the lepton pairs are formed by internal conversion of a…