Phys. Rev. Lett. 95, 142002 (2005) [5 pages]Q2 Dependence of the Neutron Spin Structure Function g2n at Low Q2Received 7 June 2005; published 29 September 2005 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)2≤Q2≤1.34 (GeV/c)2 at x≃0.2. 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. © 2005 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevLett.95.142002
DOI:
10.1103/PhysRevLett.95.142002
PACS:
13.60.Hb, 13.88.+e, 14.20.Dh, 24.85.+p
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