Extended vector meson dominance model for the baryon octet electromagnetic form factors.

Abstract

An unresolved issue in the present understanding of nucleon structure is the effect of hidden strangeness on electromagnetic observables such as ${\mathit{G}}_{\mathit{E}}^{\mathit{n}}$(${\mathit{q}}^{2}$). Previously, we have shown that ${\mathit{G}}_{\mathit{E}}^{\mathit{n}}$(${\mathit{q}}^{2}$) is sensitive to small \ensuremath{\varphi}NN couplings. A complementary approach for understanding effects due to strangeness content and the Okubo-Zweig-Iizuka (OZI) rule is to investigate the electromagnetic structure of hyperons. We apply Sakurai's universality limit of the SU(3${)}_{\mathit{F}}$ symmetry relations and a prescription based on the OZI rule to calculate the electromagnetic form factors of the baryon octet states (p,n,\ensuremath{\Lambda},${\mathrm{\ensuremath{\Sigma}}}^{+}$,${\mathrm{\ensuremath{\Sigma}}}^{0}$,${\mathrm{\ensuremath{\Sigma}}}^{\mathrm{\ensuremath{-}}}$,${\mathrm{\ensuremath{\Xi}}}^{0}$,${\mathrm{\ensuremath{\Xi}}}^{\mathrm{\ensuremath{-}}}$) within the framework of an extended vector meson dominance model. To provide additional motivation for experimental investigation, we discuss the possibility of extracting the ratio ${\mathit{G}}_{\mathit{M}}^{\mathrm{\ensuremath{\Lambda}}}$(${\mathit{q}}^{2}$)/${\mathit{G}}_{\mathit{M}}^{\mathrm{\ensuremath{\Sigma}}\mathrm{\ensuremath{\Lambda}}}$(${\mathit{q}}^{2}$) from the \ensuremath{\Lambda}/\ensuremath{\Sigma} polarization ratio in kaon electroproduction experiments. \textcopyright{} 1996 The American Physical Society.