Recoil order chiral corrections to baryon octet axial vector currents and large Nc QCD

We compute the chiral corrections to octet baryon axial vector currents through O(p3) in heavy baryon chiral perturbation theory, including both octet and decuplet baryon intermediate states. We include the latter in a consistent way by using the small scale expansion. We find that, in contrast to the situation at O(p2), there exist no cancellations between octet and decuplet contributions at O(p3). Consequently, the O(p3) corrections spoil the expected scaling behavior of the chiral expansion. We discuss this result in terms of the 1/Nc expansion. We also consider the implications for the determination of the strange quark contribution to the nucleon spin from polarized deep inelastic scattering data.