Phenomenological delineation of the quark-gluon structure from nucleon electromagnetic form factors

Abstract

We investigate a synthesis of topological chiral models with the vector meson dominance idea, with applications to nucleon and pion electromagnetic form factors. We suggest that the large tensor coupling of the ρ-meson to the nucleon, about twice that given by the vector dominance model, is an indicator of quark-gluon substructure of the nucleon at distances ≲ 1 2 fm . Nucleon and pion form factors are fit within this model, which implies that the γ-ray coupling is about 50% directly to the intrinsic quark structure of the nucleon or pion, and the other 50% is indirect, through vector mesons.