Measurements of d2n and A1n: Probing the neutron spin structure

We report on the results of the E06-014 experiment performed at Jefferson Lab in Hall A, where a precision measurement of the twist-3 matrix element d2 of the neutron (d2n) was conducted. The quantity d2n represents the average color Lorentz force a struck quark experiences in a deep inelastic electron scattering event off a neutron due to its interaction with the hadronizing remnants. This color force was determined from a linear combination of the third moments of the He3 spin structure functions, g1 and g2, after nuclear corrections had been applied to these moments. The structure functions were obtained from a measurement of the unpolarized cross section and of double-spin asymmetries in the scattering of a longitudinally polarized electron beam from a transversely and a longitudinally polarized He3 target. The measurement kinematics included two average Q2 bins of 3.2 GeV2 and 4.3 GeV2, and Bjorken-x 0.25≤x≤0.90 covering the deep inelastic and resonance regions.