Measurement of the proton electric to magnetic form factor ratio from   \vec ^1H(\vec e, e'p)
  We report the first precision measurement of the proton electric to magnetic form factor ratio from spin-dependent elastic scattering of longitudinally polarized electrons from a polarized hydrogen internal gas target. The measurement was performed at the MIT-Bates South Hall Ring over a range of four-momentum transfer squared $Q^2$ from 0.15 to 0.65 (GeV/c)$^2$. Significantly improved results on the proton electric and magnetic form factors are obtained in combination with previous cross-section data on elastic electron-proton scattering in the same $Q^2$ region. 
C.B. Crawford, A. Sindile, T. Akdogan, R. Alarcon, W. Bertozzi, E.   Booth, T. Botto, J. Calarco, B. Clasie, A. DeGrush, T.W...