Measurement of Born cross section of e^+e^- ^+^- at center-of-mass energies between 3. 510 and 4. 951 GeV

A bstract Using 24. 1 fb − 1 of e + e − collision data collected with the BESIII detector at the BEPCII collider, the Born cross sections and effective form factors of the e^+e^- ^+^- e + e − → Σ + Σ ¯ − reaction are measured. The measurements are performed at center-of-mass energies ranging from 3. 510 to 4. 951 GeV. No significant evidence for the decay of the charmonium (-like) states, ψ (3770), ψ (4040), ψ (4160), Y (4230), Y (4360), ψ (4415), and Y (4660), into a ^+^- Σ + Σ ¯ − final state is observed. Consequently, upper limits for the products of the branching fractions and the electronic partial widths at the 90% confidence level are reported for these decays.