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arXiv · 0706.3509

Two-component model for the axial form factor of the nucleon

C. Adamuščín·E. Tomasi-Gustafsson·E. Santopinto·R. Bijker
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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$^2$, but they surprisingly show a zero between 2 and 3 GeV$^2$. 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.

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C. Adamuščín, E. Tomasi-Gustafsson, E. Santopinto, R. Bijker. 2008-08-20. Two-component model for the axial form factor of the nucleon. https://doi.org/10.1103/physrevc.78.035201

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