Spin-Parity Analysis of ppbar Mass Threshold Structure in J/psi and psi' Radiative Decays

BESIII Collaboration

A partial wave analysis of the $p\bar{p}$ mass-threshold enhancement in the reaction $J/\psi \to \gamma p\bar{p}$ is used to determine: its $J^{PC}$ quantum numbers to be $0^{-+}$; i…