Volume Dependence of the Axial Charge of the Nucleon
  It is shown that the strong volume-dependence of the axial charge of the nucleon seen in lattice QCD calculations can be understood quantitatively in terms of the pion-induced interactions between neighbouring nucleons. The associated wave function renormalization leads to an increased suppression of the axial charge as the strength of the interaction increases, either because of a decrease in lattice size or in pion mass. 
N. L. Hall, A. W. Thomas, R. D. Young and J. M. Zanotti
hep-lat hep-ph nucl-th