U-spin considerations to guess the unknown time-like neutron form factors

The neutron time-like form factors have never been measured. Perturbative QCD, extended vector meson dominance and other models give very different predictions. The available data on Λ form factor and J/Ψ→Banti B allow an estimation of the neutron time-like form factors according to the U-spin symmetry. At the threshold a large neutron magnetic form factor comes out, likely falling steeper than the proton one. (orig.)