Observation of $e^{+}e^{-} \rightarrow K\bar{K}J/ψ$ at center-of-mass energies from 4.189 to 4.600 GeV

Abstract

We investigate the process $e^{+}e^{-} \rightarrow K\bar{K}J/ψ$ at center-of-mass energies from 4.189 to 4.600 GeV using 4.7 fb$^{-1}$ of data collected by the BESIII detector at the BEPCII collider. The Born cross sections for the reactions $e^{+}e^{-} \rightarrow K^{+}K^{-}J/ψ$ and $K_{S}^{0} K_{S}^{0} J/ψ$ are measured as a function of center-of-mass energy. The energy dependence of the cross section for $e^{+}e^{-} \rightarrow K^{+}K^{-}J/ψ$ is shown to differ from that for $π^{+}π^{-}J/ψ$ in the region around the $Y(4260)$. In addition, there is evidence for a structure around 4.5 GeV in the $e^{+}e^{-} \rightarrow K^{+}K^{-}J/ψ$ cross section that is not present in $π^{+}π^{-}J/ψ$.

8 pages, 3 figures