Measurements of Σ⁺ and Σ⁻ time-like electromagnetic form factors for center-of-mass energies from 2.3864 to 3.0200 GeV

The Born cross sections of the e⁺e⁻→Σ⁺Σ¯⁻ and e⁺e⁻→Σ⁻Σ¯⁺ processes are determined for center-of-mass energy from 2.3864 to 3.0200 GeV with the BESIII detector. The cross section lineshapes can be described properly by a pQCD function and the resulting ratio of effective form factors for the Σ⁺ and Σ⁻ is consistent with 3. In addition, ratios of the Σ⁺ electric and magnetic form factors, |G_E/G_M|, are obtained at three center-of-mass energies through an analysis of the angular distributions. These measurements, which are studied for the first time in the off-resonance region, provide precision experimental input for understanding baryonic structure. The observed new features of the Σ^± form factors require more theoretical discussions for the hyperons.