In the technical reports of Panda, The Orsay hadronic physics group have proposed to measure the electromagnetic time-like form factors of the proton via the $p \bar{p}$ annihilation into $e^{+}e^{-}$ reaction. The physics interest of the two-body hadronics channels is also emphasized in order to complete a full physics program of our letter of intent. The event generators for the two-body hadronic reactions are investigated in this report