We present the first measurement of the Q2 dependence of the neutron spin structure function g2n at five kinematic points covering 0.57(GeV/c) 2â‰Q2â‰1.34(GeV/c)2 at xâ‰σ0.2. Though the naive quark-parton model predicts g2=0, nonzero values occur in more realistic models of the nucleon which include quark-gluon correlations, finite quark masses, or orbital angular momentum. When scattering from a noninteracting quark, g2n can be predicted using next-to-leading order fits to world data for g1n. Deviations from this prediction provide an opportunity to examine QCD dynamics in nucleon structure. Our results show a positive deviation from this prediction at lower Q2, indicating that contributions such as quark-gluon interactions may be important. Precision data obtained for g1n are consistent with next-to-leading order fits to world data.
|Journal||Physical Review Letters|
|State||Published - Sep 30 2005|
ASJC Scopus subject areas
- Physics and Astronomy (all)