A bstract 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, KK K K ¯, KK K K ¯ π, KJ/ψ, πJ/ψ, and KπJ/ψ seen at individual energy points or in the combined data sample.
Ablikim et al. (Wed,) studied this question.