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

TL;DR

This study measures the cross sections of $e^{+}e^{-} ightarrow Kar{K}J/\psi$ at energies 4.189-4.600 GeV, revealing differences from $\pi^{+}\pi^{-}J/\psi$ and evidence for a new structure near 4.5 GeV.

Contribution

First measurement of $Kar{K}J/\psi$ production cross sections in this energy range, showing unique energy dependence and potential new resonance structure.

Findings

Cross sections measured at various energies.

Distinct energy dependence from $\pi^{+}\pi^{-}J/\psi$.

Evidence for a structure around 4.5 GeV.

Abstract

We investigate the process $e^{+}e^{-} \rightarrow K\bar{K}J/\psi$ 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 $e^{+}e^{-} \rightarrow K^{+}K^{-}J/\psi$ and $K_{S}^{0} K_{S}^{0} J/\psi$ are measured as a function of center-of-mass energy. The energy dependence of the cross section for $e^{+}e^{-} \rightarrow K^{+}K^{-}J/\psi$ is shown to differ from that for $\pi^{+}\pi^{-}J/\psi$ in the region around the $Y(4260)$. In addition, there is evidence for a structure around 4.5 GeV in the $e^{+}e^{-} \rightarrow K^{+}K^{-}J/\psi$ cross section that is not present in $\pi^{+}\pi^{-}J/\psi$.