Speaker
Description
The neutron spin asymmetry, An1 , serves as a pivotal observable for exploring the spin structure of the nucleon. Recent experiments at Jefferson Lab employing polarized 3He targets have extracted An1 over an extended kinematic range into larger xB , while maintaining high statistical precision. The experiment was carried out in Hall C with up to 10.386 GeV polarized electron beams scattering from a longitudinally polarized 3He target, focusing primarily on An1 ,followed by a secondary overview of the dn2 moment. Preliminary A 3He1 results, now available from two PhD theses, form the baseline for our current analysis. Over the
past year, efforts have concentrated on radiative corrections—requiring comprehensive input models of 3He structure functions spanning the deep-inelastic, resonance, and quasi-elastic regions. To this end, we developed two approaches: one combining smeared proton and neutron fits and applying nuclear smearing under the weak-binding approximation, and second is a direct fit to world 3He data. We find that polarized quasi-elastic contributions must be modeled carefully for the dn2 radiative corrections,
while their direct impact on An1 radiative correction remains minimal.
This talk aims to synthesize current advancements, address theoretical and experimental challenges, and elucidate how forthcoming measurements at Jefferson Lab will further our comprehension of the neutron's spin structure.
