Chronology of Milestone Events in Particle Physics - ASHMAN 1988B
Chronology of Milestone Events in Particle Physics

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

Related references
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Reactions
  + p + X 1.5-70 GEV2 (Q2) asym

Record comments
Evidence for complex spin structure of the proton, "proton spin crisis''.
    
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