Electromagnetic form factors of $Σ^{+}$ and $Σ^{-}$ in the vector meson dominance model

Abstract: Based on the recently measurements of the $e^{+} e^{-} \to \Sigma^{+} \bar{\Sigma}^{-}$ and $e^{+} e^{-} \to \Sigma^{-} \bar{\Sigma}^{+}$ processes, the electromagnetic form factors of the hyperon $\Sigma^+$ and $\Sigma^-$ in the timelike region are investigate by using the vector meson dominance model. We have included the contributions from the $\rho$, $\omega$ and $\phi$ mesons. The model parameters are determined with the BESIII experimental data on the timelike effective form factors $|G_{\rm eff}|$ of $\Sigma^{+}$ and ${\Sigma}^{-}$ for center-of-mass energy from 2.3864 to 3.02 GeV. Then, we analytically continue the electromagnetic form factors to spacelike region and evaluate the spacelike form factors of $\Sigma^+$ and $\Sigma^-$. The obtained electromagnetic form factors of the $\Sigma^+$ and $\Sigma^-$ baryons are comparable with other model calculations.