[en] Color polarizabilities of the neutron are extracted from data on the lowest moment of the spin-dependent g1 structure function. New data in the resonance region from Jefferson Lab at Q² <∼ 1 GeV², in combination with world data at higher Q², allow a systematic determination of the 1/Q² corrections, and provide the first constraints on 1/Q⁴ corrections. The results suggest that higher-twist effects in the neutron are surprisingly small, and that quark-hadron duality may be approximately valid, even down to Q² ∼ 0.5 GeV²

[en] We extract the Bjorken integral Γ₁^p-n in the range 0.17 < Q² < 1.10 GeV² from inclusive scattering of polarized electrons by polarized protons, deuterons and ³He, for the region in which the integral is dominated by nucleon resonances. These data bridge the domains of the hadronic and partonic descriptions of the nucleon. In combination with earlier measurements at higher Q², we extract the non-singlet twist-4 matrix element f₂

[en] The structure functions g₁^p and g₁ⁿ have been measured over the range 0.014 < x < 0.9 and 1 < Q² < 40 GeV² using deep-inelastic scattering of 48 GeV longitudinally polarized electrons from polarized protons and deuterons. We find that the Q² dependence of g₁^p (g₁ⁿ) at fixed x is very similar to that of the spin-averaged structure function F₁^p (F₁ⁿ). From a NLO QCD fit to all available data we find Γ₁^p - Γ₁ⁿ = 0.176 ± 0.003 ± 0.007 at Q² = 5 GeV², in agreement with the Bjorken sum rule prediction of 0.182 ± 0.005

[en] We have measured the transverse asymmetry A_T' in the quasi-elastic ³/rvec He/(/rvec e/,e') process with high precision at Q²-values from 0.1 to 0.6 (GeV/c)². The neutron magnetic form factor G_Mⁿ was extracted at Q²-values of 0.1 and 0.2 (GeV/c)² using a non-relativistic Faddeev calculation which includes both final-state interactions (FSI) and meson-exchange currents (MEC). Theoretical uncertainties due to the FSI and MEC effects were constrained with a precision measurement of the spin-dependent asymmetry in the threshold region of ³/rvec He/(/rvec e/,e'). We also extracted the neutron magnetic form factor G_Mⁿ at Q²-values of 0.3 to 0.6 (GeV/c)² based on Plane Wave Impulse Approximation calculations

[en] We have measured the transverse asymmetry from inclusive scattering of longitudinally polarized electrons from polarized ³He nuclei at quasi-elastic kinematics in Hall A at Jefferson Lab with high statistical and systematic precision. The neutron magnetic form factor was extracted based on Faddeev calculations with an experimental uncertainty of less than 2%

[en] We have measured the proton and deuteron spin structure functions g₁^p and g₁^d in the region of the nucleon resonances for W² < 5 GeV² and Q² ≅ 0.5 and Q² ≅ 1.2 GeV² by inelastically scattering 9.7 GeV polarized electrons off polarized ¹⁵NH₃ and ¹⁵ND₃ targets. We observe significant structure in g₁^p in the resonance region. We have used the present results, together with the deep-inelastic data at higher W², to extract Γ(Q²) (triple_bond) ∫₀¹ g₁(x,Q²) dx. This is the first information on the low-Q² evolution of Gamma toward the Gerasimov-Drell-Hearn limit at Q² = 0