The gluonic contribution to g1P(x,Q2) in the Parton model

We present a careful analysis of the polarized photon-gluon fusion process. Discussing various regularization schemes it is demonstrated that one can safely extract a hard gluonic contribution to the proton's spin dependent structure function g1P. The value of the first moment of the gluonic Wilson coefficient is shown to be in agreement with the anomaly result. Furthermore, we examine the question whether the gluonic contribution alone can account for existing experimental data for g1P(x, Q2) (x≥0.01, ≅Q02=10 GeV2) and find a positive answer. (orig.)