Remarks on Next-to-Leading Order Analysis of Polarized Deep Inelastic Scattering Data

Since the x dependence of the axial-anomaly effect in inclusive polarized deep inelastic scattering is fixed, the transformation from the MS scheme to different factorization schemes are not arbitrary. If the quark spin distribution is demanded to be anomaly-free so that it does not evolve with Q and hard gluons contribute to the first moment of g1(x), then all the moments of coefficient and splitting functions are fixed by perturbative QCD for a given γ5 prescription, contrary to the commonly used Adler-Bardeen (AB) or AB-like scheme. It is urged that, in order to correctly demonstrate the effect of factorization scheme dependence, the QCD analysis of polarized structure functions in next-to-leading order should be performed, besides the MS scheme, in the chiral-invariant factorization scheme in which the axial anomaly resides in the gluon coefficient function.