New approach to axial coupling constants in the QCD sum rule

We derive new QCD sum rules for the axial coupling constants by considering the correlation functions of axial-vector currents in a one-nucleon state. The QCD sum rules tell us that the axial coupling constants are expressed by nucleon matrix elements of quark-gluon composite operators which are related to the sigma terms and the moments of parton distributions. The results for the isovector axial coupling constants and the eighth component of the SU(3)(f) octet are in good agreement with experiment.