Observation of ${\eta }_c$(1S, 2S) and ${\chi }_{cJ}$ decays to 2$({\pi }^{+}{\pi }^{-})\eta$ via $\psi$(3686) radiative transitions

BESIII Collaboration, M. Ablikim, M. N. Achasov +642

Based on $2.7\times 10^9\psi (3686)$ decays collected with the BESIII detector, the radiative decay $\psi (3686)\to \gamma 2({\pi }^{+}{\pi }^{-})\eta$ is investigated to measure properties of S- and P…