Observation of the Exotic State $\ddot{I}{€}_1(1600)$ in $\ddot{I}ˆ(2S)\to {\hat{I}}^3\ddot{I}{‡}_{c1},\ddot{I}{‡}_{c1}\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}\hat{I}{\cdot }^{\prime }$

BESIII Collaboration, M. Ablikim, M. N. Achasov +750

A partial wave analysis of the process $\ddot{I}ˆ(2S)\to {\hat{I}}^3\ddot{I}{‡}_{c1},\ddot{I}{‡}_{c1}\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}\hat{I}{\cdot }^{\prime }$ is performed using $(2712.4\pm 14.3)\times 10^6$ $\ddot{I}ˆ(2S)$ events collecte…