Q{sup 2} Dependence of the Neutron Spin Structure Function g{sub 2}{sup n} at Low Q{sup 2}
- College of William and Mary, Williamsburg, Virginia 23187 (United States)
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); and others
We present the first measurement of the Q{sup 2} dependence of the neutron spin structure function g{sub 2}{sup n} at five kinematic points covering 0.57 (GeV/c){sup 2}{<=}Q{sup 2}{<=}1.34 (GeV/c){sup 2} at x{approx_equal}0.2. Though the naive quark-parton model predicts g{sub 2}=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, g{sub 2}{sup n} can be predicted using next-to-leading order fits to world data for g{sub 1}{sup n}. 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 Q{sup 2}, indicating that contributions such as quark-gluon interactions may be important. Precision data obtained for g{sub 1}{sup n} are consistent with next-to-leading order fits to world data.
- OSTI ID:
- 20696517
- Journal Information:
- Physical Review Letters, Vol. 95, Issue 14; Other Information: DOI: 10.1103/PhysRevLett.95.142002; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
- Country of Publication:
- United States
- Language:
- English
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