The electromagnetic form factors of Σ and Σ⁰ → Λ transition in the timelike region

We investigate the e⁺e^- → ΣΣ and e⁺e^- → ΛΣ⁰ reactions within the extended vector meson dominance model. In addition to the ground state mesons ρ and ω, we consider the contributions of the excited states ρ(3D), ω(3D), φ(3D), and ρ(2850). It is found that the current experimental data on the Σ electromagnetic form factors in timelike region can be well reproduced. And the φ(3D) resonance is essential to the near threshold enhancement of the cross section for the e⁺e^- → ΣΣ reaction. Furthermore, in the e⁺e^- → ΛΣ⁰ reaction, the ρ(3D) is important to get a good fit for the experimental results.