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ASHMAN 1988B

EMC Collaboration; Ashman, J.G. et al.
A Measurement of the Spin Asymmetry and Determination of the Structure Function g₁ in Deep Inelastic Muon-Proton Scattering.
Phys. Lett. 206B (1988) 364;

Abstracts
The spin asymmetry in deep inelastic scattering of longitudinally polarized muons by longitudinally polarized protons has been measured over a large (0.01 < x < 0.7). The spin-dependent structure function g₁(x) for the proton has been determined and its integral over x found to be 0.114 ± 0.012 ± 0.026, in disagreement with the Ellis-Jaffe sum rule. Assuming the validity of the Bjorken sum rule, this result implies a significant negative value for the integral of g₁ for the neutron. These values for the integrals of g₁ lead to the conclusion that the total quark spin constitutes a rather small fraction of the spin of the nucleon.

Accelerator CERN-SPS Detectors EMC

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