International Conference on Exotic Atoms and Related Topics - EXA2017

The $p\overline{p}$ invariant mass spectra of the processes $J/\psi \to p\overline{p}{\pi }^0$, $J/\psi \to p\overline{p}\eta$, $J/\psi \to p\overline{p}\omega$, $J/\psi \to p\overline{p}\rho$, and $J/\psi \to p\overline{p}\gamma$ close to the $p\overline{p}$ threshold are calculated by means of the $N\overline{N}$ optical potential. The simple potential model for $N\overline{N}$ interaction in the ${}^1{S}_0$ and ${}^3{S}_1$ states is proposed. The parameters of the model are obtained by fitting the cross sections of $N\overline{N}$ scattering together with the cross sections of $N\overline{N}$ production in $e^{+}{e}^{-}$ annihilation and the $p\overline{p}$ invariant mass spectra of the $J/\psi$ decays. Good agreement with the available experimental data is achieved. Using our potential and the Green's function approach we also describe the peak in the ${\eta }^{\prime }{\pi }^{+}{\pi }^{-}$ invariant mass spectrum in the decay $J/\psi \to \gamma {\eta }^{\prime }{\pi }^{+}{\pi }^{-}$ in the energy region near the $N\overline{N}$ threshold.