New results on the spin structure function g1 of the proton and the deuteron from SMC

1998

Abstract New results from a measurement of the spin-dependent structure function g 1 p by the SMC are presented. A next-to-leading order QCD analysis of all published data is used to compute g 1 p at a fixed Q 2 of 10 GeV 2 . Two methods for the extrapolation towards x = 0 to determine the first moment are discussed. In both cases the violation of the Ellis-Jaffe sum rule is confirmed. Using the deuteron data in addition the Bjorken sum rule is tested.