Delocalization of the axial charge in the chiral limit

The nucleon's axial vector charge, g A , becomes delocalized in the chiral limit. When m π = 0, and SU (2) L ×SU (2) R is exact, 1/3 of the nucleon's axial charge is to be found at infinite distance from the nucleon. For finite m π this result is approached smoothly as m π → 0. We illustrate this effect by considering the lepton-proton spin-spin interaction arising from Z 0 exchange as a function of m π. Delocalization may have implications for lattice calculations of g A and in nuclei.