[en] We report the results of a new Rosenbluth measurement of the proton form factors at Q² values of 2.64, 3.20 and 4.10 GeV². Cross sections were determined by detecting the recoiling proton in contrast to previous measurements in which the scattered electron was detected. At each Q², relative cross sections were determined to better than 1%. The measurement focused on the extraction of G_E/G_M which was determined to 4-8% and found to approximate form factor scaling, i.e. μ_pG_E ∼ G_M. These results are consistent with and much more precise than previous Rosenbluth extractions. However, they are inconsistent with recent polarization transfer measurements of comparable precision, implying a systematic difference between the two techniques

[en] We measured the angular dependence of the three recoil proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily.. Transverse polarizations are not well described, but suggest isovector dominance

[en] We have measured the proton recoil polarization in the ⁴He(polarized-e, e-prime, p)³H reaction at Q² = 0.5, 1.0, 1.6, and 2.6 (GeV/c)². The measured ratio of polarization transfer coefficients differs from a fully relativistic calculation, favoring the inclusion of a predicted medium modification of the proton form factors based on a quark-meson coupling model. In contrast, the measured induced polarizations agree reasonably well with the fully relativistic calculation indicating that the treatment of final-state interactions is under control

[en] The first complete measurements of the angular distributions of the two-body deuteron photodisintegration differential cross section at photon energies above 1.6 GeV were performed at the Thomas Jefferson National Accelerator Facility. The results show a persistent forward-backward asymmetry up to Egamma = 2.4 GeV, the highest-energy measured in this experiment. The Hard Rescattering and the Quark-Gluon string models are in fair agreement with the results

[en] The ratio of the proton's elastic electromagnetic form factors, G_Ep/G_Mp, was obtained by measuring P_t and P_ell, the transverse and longitudinal recoil proton polarization components, respectively, for the elastic (rvec e)p → e(rvec p) reaction in the four-momentum transfer squared range of 0.5 to 3.5 GeV². In the single photon exchange approximation, the ratio G_Ep/G_Mp is directly proportional to the ratio P_t/P_ell. The simultaneous measurement of P_t and P_#ell# in a polarimeter reduces systematic uncertainties. The results for the ratio G_Ep/G_Mp show a systematic decrease with increasing Q², indicating for the first time a definite difference in the distribution of charge and magnetization in the proton. The data have been reanalyzed and systematic uncertainties have become significantly smaller than previously published results

[en] The deuteron elastic structure function A(Q²) has been extracted in the range 0.7 < or = Q² < or = 6.0 (GeV/c)² from cross section measurements of elastic electron-deuteron scattering in coincidence using the Hall A Facility of Jefferson Laboratory. The data are compared to theoretical models, based on the impulse approximation with the inclusion of meson-exchange currents, and to predictions of quark dimensional scaling and perturbative quantum chromodynamics