Observation of a structure at 1.84 GeV/c${}^2$ in the $3({\pi }^{+}{\pi }^{-})$ mass spectrum in $J/\psi \to \gamma 3({\pi }^{+}{\pi }^{-})$ decays

BESIII Collaboration, M. Ablikim, M. N. Achasov +362

With a sample of 225.3 million $J/\psi$ events taken with the BESIII detector, the decay $J/\psi \to \gamma 3({\pi }^{+}{\pi }^{-})$ is analyzed. A structure at 1.84 GeV/c${}^2$ is observed in the $3(π…