Measurement of the e⁺e⁻ → K_s⁰ K^± π^∓ π⁰ and K_s⁰ K^± π^∓η Cross Sections Using Initial-State Radiation

The processes e⁺e⁻ → K_s⁰ K^± π^∓ π⁰ and e⁺e⁻ → K_s⁰ K^± π^∓η are studied over a continuum of energies from threshold to 4 GeV with the initial-state photon radiation method. Using 454 fb⁻¹ of data collected with the BABAR detector at the SLAC PEP-II storage ring, the first measurements of the cross sections for these processes are obtained. The intermediate resonance structures from K⁰ (Kπ)⁰, K(892)^±(Kπ)^∓, and K_s⁰ K^± ρ^∓ are studied. The J/ψ is observed in all of these channels, and corresponding branching fractions are measured.