First Measurement of the Branching Ratio of $J/\psi \to \gamma f_2(1270)f_2(1270)$

BES Collaboration, M. Ablikim

Using 58 million $J/\psi$ events taken with the BES II detector at the Beijing Electron Positron Collider, a new decay mode $J/\psi \to \gamma f_2(1270)f_2(1270)\to \gamma {\pi }^{+}{\pi }^{-}{\pi }^{+}{\pi }^{-}$ is obser…