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

Zhi-Gang Wang; Shao-Long Wan; Wei-Min Yang

doi:10.1140/epjc/s2006-02570-2

paper

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

arXiv:hep-ph/0601060 · doi:10.1140/epjc/s2006-02570-2

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 $Q^{2} > 2 G e V^{2}$ 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.

21 pages, 12 figures, revised version