Measurement of the neutron spin structure function g and asymmetry A

We have measured the neutron structure function g2n and the virtual photon-nucleon asymmetry A2n over the kinematic range 0.014 ⩽ × ⩽ 0.7 and 1.0 ⩽ Q2 ⩽ 17.0 by scattering 48.3 GeV longitudinally polarized electrons from polarized 3He. Results for A2n are significantly smaller than the √R positivity limit over most of the measured range and data for g2n are generally consistent with the twist-2 Wandzura-Wilczek prediction. Using our measured g2n we obtain results for the twist-3 reduced matrix element d2n, and the integral ∫ g2n(x) dx in the range 0.014 ⩽ × ⩽ 1.0. Data from this experiment are combined with existing data for g2n to obtain an average for d2n and the integral ∫ g2n(x) dx.