Electromagnetic form factors of Σ+ and Σ− in the vector-meson dominance model

Abstract

Abstract Based on the recent measurements of the e + e − → Σ + Σ ¯ − and e + e − → Σ − Σ ¯ + processes by the Beijing Spectrometer III (BESIII) collaboration, the electromagnetic form factors of the hyperon Σ+ and Σ− in the timelike region are investigated using the vector-meson dominance model, where the contributions of the ρ, ω, and ϕ mesons are taken into account. The model parameters are determined from the BESIII experimental data of the timelike effective form factors ∣G eff∣ of the Σ+ and Σ− baryons for center-of-mass energies from 2.3864 to 3.02 GeV. It is found that we can provide quantitative descriptions of the available data using as few as one adjustable model parameter. We then progress to an analysis of the electromagnetic form factors in the spacelike region and evaluate the spacelike form factors of the hyperons Σ+ and Σ−. The electromagnetic form factors obtained for the Σ+ and Σ− baryons are comparable with those of other model calculations.