The JLab polarization transfer measurements of proton elastic form factor

The ratio of the electric and magnetic proton form factors,GEpGMp, has been obtained in two Hall A experiments, from measurements of the longitudinal and transverse polarizations of the recoil proton,Pl andPt, in the elastic scattering of polarized electrons,\(\overrightarrow e p \to e\overrightarrow p \). Together these experiments cover theQ2 range of 0.5 to 5.6 GeV2. A new experiment is currently being prepared, to extend theQ2 range to 9 GeV2 in Hall C.