Cross-section measurements of e+ e− → φK+ K− and e+ e− → φK0SK0S at center-of-mass energies between 3.7730 GeV and 4.7008 GeV

Based on 22.7fb−1 of e+e− annihilation data collected at 33 different center-of-mass energies between 3.7730 and 4.7008 GeV with the BESIII detector at the BEPCII collider, Born cross sections of the two processes e+e− → φK+K− and e+e− → φK0SK0S are measured for the first time. No indication of resonant production through an intermediate vector state V is observed, and the upper limits on the product of the electronic width Γe+e− and the branching fraction Br(V → φKK ̄ ) of the processes e+e− → V → φK+K− and e+e− → V → φK0SK0S at the 90% confidence level are obtained for a large parameter space in resonance masses and widths. For the current world average mass and width of the ψ(4230) of m = 4.2187 GeV/c2 and Γ = 44 MeV, we set upper limits on the φK+K− and φK0SK0S final states of 1.75 and 0.47 eV at the 90% confidence level, respectively.