Results for the isovector axial form factors of the proton from a lattice QCD calculation are presented for both point-split and local currents. They are obtained on a quenched 163×24 lattice at β=6.0 with Wilson fermions for a range of quark masses from strange to charm. We determine the finite lattice renormalization for both the local and point-split currents of heavy quarks. Results extrapolated to the chiral limit show that the q2 dependence of the axial form factor agrees reasonably well with experiment. The axial coupling constant gA calculated for the local and the point-split currents is about 6\% and 12\% smaller than the experimental value respectively.
@article{arxiv.hep-lat/9305025,
title = {Nucleon Axial Form Factor from Lattice QCD},
author = {K. F. Liu and S. J. Dong and T. Draper and J. M. Wu and W. Wilcox},
journal= {arXiv preprint arXiv:hep-lat/9305025},
year = {2009}
}