Observation of vector charmoniumlike states and search for Zcs in e⁺ e⁻ → K⁺ K⁻ J/ψ at BESIII

We present the recent measurements of the e⁺e⁻→ K⁺K⁻ J/ψ process carried out by the BESIII experiment. A new decay mode Y(4230)→ K⁺K⁻ J/ψ is firstly identified by BESIII. Furthermore, two vector charmoniumlike states, $Y(4500)$ and $Y(4710)$, are reported for the first time in the energy-dependent line shape of e⁺e⁻→ K⁺K⁻ J/ψ cross section. In additon, an investigation of the K^± J/ψ system is conducted to explore charged charmoniumlike states.