Contribution of the a1 meson to the axial nucleon-to-delta transition form factors

Ünal, Y. (Physics Department, Çanakkale Onsekiz Mart University, 17100 Çanakkale, Turkey) ; Küçükarslan, A. (Physics Department, Çanakkale Onsekiz Mart University, 17100 Çanakkale, Turkey) ; Scherer, S. (PRISMA Cluster of Excellence, Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany)

11 January 2019

Abstract: We analyze the low-Q2 behavior of the axial form factor GA(Q2), the induced pseudoscalar form factor GP(Q2), and the axial nucleon-to-delta transition form factors C5A(Q2) and C6A(Q2). Building on the results of chiral perturbation theory, we first discuss GA(Q2) in a chiral effective-Lagrangian model including the a1 meson and determine the relevant coupling parameters from a fit to experimental data. With this information, the form factor GP(Q2) can be predicted. For the determination of the transition form factor C5A(Q2), we make use of an SU(6) spin-flavor quark-model relation to fix two coupling constants such that only one free parameter is left. Finally, the transition form factor C6A(Q2) can be predicted in terms of GP(Q2), the mean-square axial radius rA2, and the mean-square axial nucleon-to-delta transition radius rANΔ2.


Published in: Physical Review D 99 (2019)
Published by: APS
DOI: 10.1103/PhysRevD.99.014012
arXiv: 1808.03046
License: CC-BY-4.0



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