Axial form-factor and induced pseudoscalar form-factor of the nucleons

Abstract

In this article, we calculate the axial and the induced pseudoscalar form-factors $G_A(t=-Q^2)$ and $G_P(t=-Q^2)$ of the nucleons in the framework of the light-cone QCD sum-rules approach up to twist-6 three valence quark light-cone distribution amplitudes, and observe that the form-factors $G_A(t=-Q^2)$ and $G_P(t=-Q^2)$ at intermediate and large momentum transfers with $Q^2> 2 GeV^2$ have significant contributions from the end-point (soft) terms. The numerical values for the axial form-factor $G_A(t=-Q^2)$ are compatible with the experimental data and theoretical calculations, for example, the chiral quark models and lattice QCD. The numerical values for the induced pseudoscalar form-factor $G_P(t=-Q^2)$ are compatible with the calculation from the Bethe-Salpeter equation.