Polarized quarks, gluons and sea in nucleon structure functions,” Prog. Theor. Phys. 99

We perform a NLO analysis of polarized deep inelastic scattering data to test two different solutions to the so-called spin crisis, one of them based on the axial gluon anomaly and consistent with the Bjorken sum rule, and another in which the defects in the spin sum rules and in the Gottfried sum rule are related. In this case a defect is also expected for the Bjorken sum rule. The first solution is slightly favoured by the SLAC El54 results, but both options seem to be consistent with the CERN SMC data. The EMC experiment on gf(x) 1) has given for the first moment of the spin dependent proton structure function g{ ' (x) at (Q2) = lO Ge V2 rr = 11 gf(x) dx = 0.126 ± O.OlO ± 0.015, (1) a value much smaller than the prediction of the Ellis-Jaffe sum rule 2) for the proto