Measurement of the 3He spin-structure functions and of neutron ( 3He) spin-dependent sum rules at 0.035?≤? Q 2?≤?0.24 GeV 2

摘要

The spin-structure functionsg1andg2, and the spin-dependent partial cross-sectionσTThave been extracted from the polarized cross-sections differences,Δσ∥(ν,Q2)andΔσ⊥(ν,Q2)measured for theHe3→(e→,e′)Xreaction, in the E97-110 experiment at Jefferson Lab. Polarized electrons with energies from 1.147 to 4.404 GeV were scattered at angles of6°and9°from a longitudinally or transversely polarized3He target. The data cover the kinematic regions of the quasi-elastic, resonance production and beyond. From the extracted spin-structure functions, the first momentsΓ1￣(Q2),Γ2(Q2)andITT(Q2)are evaluated with high precision for the neutron in theQ2range from 0.035 to0.24GeV2. The comparison of the data and the chiral effective field theory predictions reveals the importance of proper treatment of the Δ degree of freedom for spin observables.