Nucleon electromagnetic form factors in nonlocal chiral effective theory

Abstract

In this paper, we calculate the pion one-loop corrections to the electromagnetic form factors of the nucleon up to $\mathcal{O}(p^4)$ order in the nonlocal framework. To systematically investigate the role of vector-meson dominance in the model, we also include the leading-order nucleon-vector-meson coupling. Owing to the renormalization-scheme dependence of chiral low-energy coupling constants (LECs), we refit these constants to the nucleon magnetic moments, electromagnetic radii, and the $Q^2$-dependence of the electromagnetic form factors. Compared with the previous local analysis, the model results show that, in the nonlocal framework, the $Q^2$-dependence of the electromagnetic form factors in the large-$Q^2$ region is significantly improved and are consistent with experimental data.