Violation of the Bjorken Sum Rule in QCD

Stefano Forte

doi:10.1016/0370-2693(93)91522-O

paper

Violation of the Bjorken Sum Rule in QCD

arXiv:hep-ph/9211227 · doi:10.1016/0370-2693(93)91522-O

Abstract

We show that the Bjorken sum rule for the first moment of the polarized nucleon structure function $g_{1}$ is not necessarily satisfied in QCD if the axial anomaly is taken into account. We argue that nonperturbative QCD effects should lead to a violation of the sum rule of the order of the percentage isospin violation in current quark masses.

11 pages, no figures (several typos and a numerical error on pag. 5 corrected)