NEUTRON SPIN STRUCTURE STUDY AT JEFFERSON LAB HALL A

With a high-intensity highly-polarized 6 GeV electron beam, and a high-density polarized 3 He target, we have carried out a number of experiments to study the neutron spin structure at Hall A in Jefferson Lab. Taking advantage of the high luminosity of Jefferson Lab, we completed two inclusive deep-inelastic-scattering experiments this summer. In the first precision measurements were made of the spin asymmetry [Formula: see text] in the valence quark (high Bjorken x) region, and in the second higher-twist effects were studied via precision measurements of [Formula: see text]. Physics motivation and preliminary results from the first experiment will be presented and discussed. I will also present nearly final results from an earlier experiment, which measured the generalized GDH sum for the neutron in the Q 2 range of 0.1 to 1 GeV 2. Planned near-term experiments will be briefly discussed.