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

We investigate the e + e - → ΣΣ and e + e - → ΛΣ 0 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 - → ΛΣ 0 reaction, the ρ (3D) is important to get a good fit for the experimental results.