[en] The 2H(e,ep)n cross section was measured in Hall A of the Thomas Jefferson National Accelerator Facility near the top of the quasielastic peak (xBj = 0.964) at a four-momentum transfer squared, Q2 = 0.665 (GeV/c)2 (0.368GeV, W = 2.057GeV), and for recoil momenta up to 550MeV/c. The measured cross section deviates by 1-2 from a state-of-the-art calculation at low recoil momenta. At high recoil momenta the cross section is well described by the same calculation; however, in this region, final-state interactions and interaction currents are predicted to be large, and alternative choices of nucleon-nucleon potential and nucleon current operator may result in significant spread in the calculations

[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 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 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] We investigated simultaneously the 12C(e,e'p) and 12C(e,e'pp) reactions at Q2 = 2 [GeV/c]2, x_B = 1.2, and in an (e,e'p) missing-momentum range from 300 to 600 MeV/c. At these kinematics, with a missing-momentum greater than the Fermi momentum of nucleons in a nucleus and far from the delta excitation, short-range nucleon-nucleon correlations are predicted to dominate the reaction. For (9.5 +/- 2)% of the 12C(e,e'p) events, a recoiling partner proton was observed back-to-back to the 12C(e,e'p) missing momentum vector, an experimental signature of correlations

[en] The present experiment exploits the interference between the Deeply Virtual Compton Scattering (DVCS) and the Bethe-Heitler processes to extract the imaginary part of DVCS amplitudes on the neutron and on the deuteron from the helicity-dependent D((rvec e), e'γ)X cross section measured at Q²=1.9 GeV² and x_B=0.36. We extract a linear combination of generalized parton distributions (GPDs) particularly sensitive to E_q, the least constrained GPD. A model dependent constraint on the contribution of the up and down quarks to the nucleon spin is deduced

[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] Cross-section values for Compton scattering on the proton were measured at 25 kinematic settings over the range s = 5-11 and -t = 2-7 GeV2 with statistical accuracy of a few percent. The scaling power for the s-dependence of the cross section at fixed center of mass angle was found to be 8.0 +/- 0.2, strongly inconsistent with the prediction of perturbative QCD. The observed cross section values are in fair agreement with the calculations using the handbag mechanism, in which the external photons couple to a single quark