Key points are not available for this paper at this time.
The e^+e^- nn cross section was measured at center of mass (c. m. ) energies from the threshold to 1908 MeV. The experiment to measure the cross section has been carried out at the VEPP-2000 e^+e^- collider in 13 energy points. The SND detector is used to detect the produced neutron-antineutrons (nn) events. A special time measurement system on the calorimeter was used to select the time-delayed nn events. The measured e^+e^- nn cross section is 0. 4--0. 6 nb. The neutron effective timelike form factor in the energy range under study varies from 0. 3 to 0. 6.
Achasov et al. (Wed,) studied this question.