Helicity amplitude analysis of $\psi \left(3686\right)\to \gamma {\chi }_{cJ}\to \gamma p\overline{p}$

A helicity amplitude analysis for the processes $\psi \left(3686\right)\to \gamma {\chi }_{cJ}\to \gamma p\overline{p}$ is performed. The joint angular distributions for these processes are obtained, which allows a proper estimation of the detection efficiency using helicity amplitude information. The helicity amplitudes parameters for ${\chi }_{c1,2}\to p\overline{p}$ are also obtained using measured α values for the first time. In addition, the sensitivities of measurements of the helicity amplitudes parameters for these processes are discussed based on the MC simulation.