Eur. Phys. J. C (2006) 47: 375-384
https://doi.org/10.1140/epjc/s2006-02570-2

Theoretical Physics

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

¹ Department of Physics, North China Electric Power University, Baoding, 071003, P.R. China
² Department of Modern Physics, University of Science and Technology of China, Hefei, 230026, P.R. China

^* e-mail: wangzgyiti@yahoo.com.cn

Received: 10 January 2006
Revised: 6 April 2006
Published online: 19 May 2006

Abstract

We calculate the axial and the induced pseudoscalar form-factors G_A(t=-Q²) and G_P(t=-Q²) 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=-Q²) and G_P(t=-Q²) at intermediate and large momentum transfers with Q²>2 GeV² have significant contributions from the end-point (soft) terms. The numerical values for the axial form-factor G_A(t=-Q²) 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=-Q²) are compatible with the calculation from the Bethe–Salpeter equation.