Nucleon form factors and final state radiative corrections to $e^+e^-\to \bar p p \gamma$

Abstract

New parametrisation for the electric and the magnetic form factors of proton and neutron are presented. The proton form factors describe well the recent measurements by BaBar collaboration and earlier ones of the ratio of the form factors in space-like region. The neutron form factors are consistent with earlier measurements of neutron pair production and ratio of the form factors in the space-like region. These form factors are implemented into the generator PHOKHARA, which simulates the reactions $e^+e^-\to \bar p p \gamma$ and $e^+e^-\to \bar n n\gamma$. The influence of final state radiation is investigated.