First measurement of the cross sections for $e^{+}{e}^{-}\to K^0{K}^{-}{\pi }^{+}J/\psi +c.c.$ at $\sqrt{s}$ from 4.396 to 4.951 GeV

Abstract

Using $e^{+}{e}^{-}$ collision data at 19 center-of-mass energies ranging from $4.396$ to $4.951\mathrm{GeV}$ corresponding to a total integrated luminosity of $8.86{\mathrm{fb}}^{-1}$ collected by the BESIII detector, the process $e^{+}{e}^{-}\to K^0{K}^{-}{\pi }^{+}J/\psi +c.c.$ is observed for the first time, with a statistical significance of $9.4\sigma$ summing up all the data samples. For this process, the cross section and the upper limit at the $90\%$ confidence level are reported at each of the 19 center-of-mass energies.~No statistically significant vector structures are observed in the cross section line shape, nor are any intermediate states of $K\pi$, $K\bar{K}$, $K\bar{K}\pi$, $KJ/\psi$, $\pi J/\psi$, and $K\pi J/\psi$ seen at individual energy points or in the combined data sample.