SPIN STRUCTURE OF THE NUCLEON - EXPERIMENTAL RESULTS

The experimental status of the spin-dependent structure functions as o btained from deep inelastic scattering experiments at CERN, SLAC and D ESY is discussed. The data available for g(1)(p), g(1)(d) and g(1)(n) are evolved to common Q(2)=5 GeV2 and compared. The g(1) structure fun ctions are now precise enough to perform sensible QCD analysis. The pr edicted Q(2) dependence from this analysis is used to evaluate g(1)(x) at common Q(2), at which the first moment of g(1) is calculated. The extrapolation of g(1) to x=0, which is a controversial issue, is discu ssed in some detail. The results obtained in all experiments show that the Ellis-Jaffe sum rule is violated, consistent with previous observ ations. For the Bjorken sum rule we obtain: )(2))dx-l(0)(1)g(1)(n)(x,Q (0)(2))dx=0.192-/+0.021, which is good agreement with the prediction o f 0.181-/+0.003.