Final State Interaction Effects in the $e^+e^-\to N\bar{N}$ Process near   Threshold
  We use the Paris nucleon-antinucleon optical potential for explanation of experimental data in the process $e^+e^- \to p\bar p$ near threshold. It is shown that the cross section and the electromagnetic form factors are very sensitive to the parameters of the potential. It turns out that final-state interaction due to slightly modified absorptive part of the potential allows us to reproduce available experimental data. We also demonstrated that the cross section in $n\bar{n}$ channel is larger than that in $p\bar{p}$ one, and their ratio is almost energy independent up to 2.2 GeV. 
V.F. Dmitriev and A.I. Milstein