Contribution of the a(1) meson to the axial nucleon-to-delta transition form factors


Uenal Y., Kuecuekarslan A. , Scherer S.

PHYSICAL REVIEW D, vol.99, no.1, 2019 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 99 Issue: 1
  • Publication Date: 2019
  • Doi Number: 10.1103/physrevd.99.014012
  • Title of Journal : PHYSICAL REVIEW D

Abstract

We analyze the low-Q(2) behavior of the axial form factor G(A)(Q(2)), the induced pseudoscalar form factor GP(Q(2)), and the axial nucleon-to-delta transition form factors C-5(A)(Q(2)) and C-6(A) (Q(2)). Building on the results of chiral perturbation theory, we first discuss G(A)(Q(2)) in a chiral effective-Lagrangian model including the a(1) meson and determine the relevant coupling parameters from a fit to experimental data. With this information, the form factor G(P)(Q(2)) can be predicted. For the determination of the transition form factor C-5(A)(Q(2)), we make use of an S-U(6) spin-flavor quark-model relation to fix two coupling constants such that only one free parameter is left. Finally, the transition form factor C-6(A)(Q(2)) can be predicted in terms of G(P)(Q(2)), the mean-square axial radius < r(A)(2)> Ai, and the mean-square axial nucleon-todelta transition radius < r(AN Delta)(2)>.