Two-component model for the axial form factor of the nucleon
Abstract
The axial form factor of the nucleon is studied in a two-component model consisting of a three-quark intrinsic structure surrounded by a meson cloud. The experimental data in the space-like region are well reproduced with a minimal number of parameters. The results are similar to those obtained from a dipole fit up to 1 GeV, but they surprisingly show a zero between 2 and 3 GeV. Such behavior, predicted by the present model completely disagrees with the dipole parametrization. The theoretical expression for the form factor is then analytically extrapolated to the time-like region, giving the first predictions in this regime. This kinematical region is especially interesting for present and future colliders.
Keywords
Cite
@article{arxiv.0706.3509,
title = {Two-component model for the axial form factor of the nucleon},
author = {C. Adamuščín and E. Tomasi-Gustafsson and E. Santopinto and R. Bijker},
journal= {arXiv preprint arXiv:0706.3509},
year = {2008}
}
Comments
12 pages 2 figures Final version to appear in Phys. Rev. C