Target Mass Corrections to QCD Bjorken Sum Rule for Nucleon Spin Structure Functions

Abstract

We discuss the possible target mass corrections in the QCD analysis of nucleon's spin-dependent structure functions measured in the polarized deep-inelastic leptoproduction. The target mass correction for the QCD Bjorken sum rule is obtained from the Nachtmann moment and its magnitude is estimated employing positivity bound as well as the experimental data for the asymmetry parameters. We also study the uncertainty due to target mass effects in determining the QCD effective coupling constant $\alpha_s(Q^2)$ from the Bjorken sum rule. The target mass effect for the Ellis-Jaffe sum rule is also briefly discussed.