New results on the electric form factor of the proton

The longitudinal, Pl, and transverse, Pt, polarizations of the recoil proton were measured for the elastic (rvec e) p reaction in Hall A at Jlab. The ratio of the electric, GEp, to the magnetic, GMp, form factors of the proton was obtained from the ratio Pt/Pl. Using this technique, an earlier experiment [1] in Hall A at JLab measured GEp/GMp for the four-momentum transferred, Q2, from 0.5 to 3.5 GeV2 and found that above Q2 ∼0.8 GeV2 the ratio falls off linearly with Q2. New data presented here extend the measurement of GEp/GMp to Q2 = 5.6 GeV2 and shows that it continues to fall linearly with Q2