[en] Quark-Hadron duality has been experimentally demonstrated for the spin independent structure function F₂. Duality is observed when, at the same value of scaling variable x_bj, the smooth scaling curve at high momentum transfer becomes an average over the resonances at lower momentum transfer. Jefferson Lab experiment 01-012 used the polarized ³He target in Hall A for an extraction of the neutron spin structure function g₁ⁿ and the virtual photon asymmetry A₁ⁿ in the resonance region over a Q² range from 1.0 to 4.0 $(GeV/c)². Data from E01-012 combined with Deep Inelastic Scattering data will provide a test of quark-hadron duality predictions for g₁ⁿ and A₁ⁿ. This will be one of the first tests of the spin and flavor dependence of quark-hadron duality. The demonstration of duality for spin structure functions will enable us to use the resonance data to study the nucleon spin structure in the large x_bj region.

[en] Jefferson Lab experiment E01-012 measured the ³He spin-structure functions and virtual photon asymmetries in the resonance region in the momentum transfer range 1.0 < Q² < 4.0(GeV/c)². Our data, when compared with existing deep inelastic scattering data, were used to test quark-hadron duality in g₁ and A₁ for ³He and the neutron. In addition, preliminary results on the ³He spin-structure function g₂, on the Burkhardt-Cottingham sum rule and on higher twist effects through the x²-weighted moment d₂ of the neutron were presented.

[en] The Coulomb distortion effects have been for a long time neglected in deep inelastic scattering for the good reason that the incident energies were very high. But for energies in the range of earlier data from SLAC or at JLab, the Coulomb distortion could have the potential consequence of affecting the A-dependence of the EMC effect and of the longitudinal to transverse virtual photon absorption cross section ratio R(x,Q²).

[en] Thomas Jefferson National Accelerator Facility experiment E01-012 measured the 3He spin structure functions and virtual photon asymmetries in the resonance region in the momentum transfer range 1.0< Q2<4.0 (GeV/c)2. Our date, when compared with existing deep inelastic scattering data, can be used to test quark-hadron duality in g1 and A1 for 3He and the neutron. Preliminary results for A₁^3He are presented, as well as some details about the experiment

[en] Nuclear dynamics at short distances is one of the most fascinating topics of strong interaction physics. The physics of it is closely related to the understanding of the role of the QCD in generating nuclear forces at short distances, as well as of the dynamics of the superdense cold nuclear matter relevant to the interior of neutron stars. The emergence of high-energy electron and proton beams has led to significant recent progress in high-energy nuclear scattering experiments investigating the short-range structure of nuclei. These experiments, in turn, have stimulated new theoretical studies resulting in the observation of several new phenomena specific to the short-range structure of nuclei. In this article, we review recent theoretical and experimental progress in studies of short-range correlations in nuclei and discuss their importance for advancing our understanding of the dynamics of nuclear interactions at short distances.

[en] The protons and neutrons in a nucleus can form strongly correlated nucleon pairs. Scattering experiments, in which a proton is knocked out of the nucleus with high-momentum transfer and high missing momentum, show that in carbon-12 the neutron-proton pairs are nearly 20 times as prevalent as proton-proton pairs and, by inference, neutron-neutron pairs. This difference between the types of pairs is due to the nature of the strong force and has implications for understanding cold dense nuclear systems such as neutron stars.

[en] An experimental study of the 16O(e, e'K+)16N_#Lambda# reaction has been performed at Jefferson Lab. A thin film of falling water was used as a target. This permitted a simultaneous measurement of the p(e, e'K+)Λ,Σ₀ exclusive reactions and a precise calibration of the energy scale. A ground-state binding energy of 13.76 ± 0.16 MeV was obtained for 16N_#Lambda# with better precision than previous measurements on the mirror hypernucleus 16O_#Lambda#. Precise energies have been determined for peaks arising from a Lambda in s and p orbits coupled to the p1/2 and p3/2 hole states of the 15N core nucleus.