First measurement of the cross sections for e+e− → K0K−π+J/ψ + c.c. at $ \sqrt{s} $ from 4.396 to 4.951 GeV

Using e + e − collision data at 19 center-of-mass energies ranging from 4 . 396 to 4 . 951 GeV corresponding to a total integrated luminosity of 8 . 86 fb − 1 collected by the BESIII detector, the process e + e − → K 0 K − π + J/ψ + c.c. is observed for the first time, with a statistical significance of 9 . 4 σ summing up all the data samples. Here, c.c. stands for the charge conjugated mode. 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 as intermediate states of combinations of Kπ , $K\overline{K}$ , $K\overline{K}\pi$ , KJ/ψ , πJ/ψ , and KπJ/ψ seen at individual energy points or in the combined data sample.