[en] A device has been developed with moveable liquid nitrogen and liquid helium volumes that is capable of reaching over two meters into the coldest regions of a cryostat or dilution refrigerator and reliably extracting or installing a target of solid, polarized hydrogen deuteride (HD). This Transfer Cryostat incorporates a cylindrical neodymium rare-earth magnet that is configured as a Halbach dipole, which is maintained at 77 K and produces a 0.1 T field around the HD target. Multiple layers provide a hermetic 77 K-shield as the device is used to maintain a target at 2 K during a transfer between cryostats. Tests with frozen-spin HD show negligible polarization loss for either H or D over typical transfer periods. Multiple target transfers with this apparatus have shown an overall reliability of about 95% per transfer, which is a significant improvement over earlier versions of the device

[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] 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] 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

[en] We have measured the spin structure functions g₁ and g₂ of ³He in a double-spin experiment by inclusively scattering polarized electrons at energies ranging from 0.862 to 5.07 GeV off a polarized ³He target at a 15.5^o scattering angle. Excitation energies covered the resonance and the onset of the deep inelastic regions. We have determined for the first time the Q² evolution of Γ₁(Q²)=/int₀¹ g₁(x,Q²) dx, Γ₂(Q²)=/int₀¹ g₂(x,Q²) dx and d₂ (Q²) = /int₀¹ x ²[2g₁(x,Q²) + 3g₂(x,Q²)] dx for the neutron in the range 0.1 GeV² /leq Q² /leq 0.9 GeV² with good precision. Γ₁(Q²) displays a smooth variation from high to low Q². The Burkhardt-Cottingham sum rule holds within uncertainties and d₂ is non-zero over the measured range

[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