The Born cross section for the process e+e-→pp is measured using the initial state radiation technique with an undetected photon. This analysis is based on datasets corresponding to an integrated luminosity of 7.5 fb-1, collected with the BESIII detector at the BEPCII collider at center of mass energies between 3.773 and 4.600 GeV. The Born cross section for the process e+e-→pp and the proton effective form factor are determined in the pp invariant mass range between 2.0 and 3.8 GeV/c2 divided into 30 intervals. The proton form factor ratio (|GE|/|GM|) is measured in 3 intervals of the pp invariant mass between 2.0 and 3.0 GeV/c2.
- ELECTROMAGNETIC FORM-FACTORS
- OF-MASS ENERGIES