Can the observed enhancement in the mass spectrum of p \bar p in J/\psi   \to \gamma p \bar p be interpreted by a possible p \bar p bound state
  Provided the enhancement in the $p \bar{p}$ spectrum in radiative decay $J/\psi \to \gamma p \bar{p}$ observed by the BES collaboration is due to an existence of a $p \bar{p}$ molecular state, we calculate its binding energy and lifetime in the linear $\sigma$ model. We consider a possibility that the enhancement is due to a $p \bar p$ resonance which is in either S-wave or P-wave structure and compare our results with the data. 
Xiang Liu, Xiao-Qiang Zeng, Yi-Bing Ding, Xue-Qian Li, Hong Shen,   Peng-Nian Shen