Cross sections for the process $e^{+}{e}^{-}\to K_S^0{K}_S^{0}J/\psi$ at center-of-mass energies from 4.128 to 4.950 GeV are measured using data samples with a total integrated luminosity of $21.2{\mathrm{fb}}^{-1}$ collected by the BESIII detector operating at the BEPCII storage ring. The $Y(4230)$ state is observed in the energy dependence of the $e^{+}{e}^{-}\to K_S^0{K}_S^{0}J/\psi$ cross section for the first time with a statistical significance of $26.0\sigma$. In addition, an enhancement around 4.710 GeV, labeled as the $Y(4710)$, is seen with a statistical significance of $4.2\sigma$. There is no clear structure around 4.484 GeV. Using a fit with a coherent sum of three Breit-Wigner functions, we determine the mass and width of the $Y(4230)$ state to be $4226.9\pm 6.6\pm 22.0\mathrm{MeV}/c^2$ and $71.7\pm 16.2\pm 32.8\mathrm{MeV}$, respectively, and the mass and width of the $Y(4710)$ state to be $4704.0\pm 52.3\pm 69.5\mathrm{MeV}/c^2$ and $183.2\pm 114.0\pm 96.1\mathrm{MeV}$, respectively, where the first uncertainties are statistical and the second are systematic. In addition, the average Born cross section ratio $\frac{{\sigma }^{\text{Born}}(e^{+}{e}^{-}\to K_S^0{K}_S^{0}J/\psi )}{{\sigma }^{\text{Born}}(e^{+}{e}^{-}\to K^{+}{K}^{-}J/\psi )}$ is measured to be ${0.388}_{-0.028}^{+0.035}\pm 0.016$, or ${0.426}_{-0.031}^{+0.038}\pm 0.018$ if three-body phase space is considered.

• Received 12 January 2023
• Accepted 19 April 2023

DOI:https://doi.org/10.1103/PhysRevD.107.092005

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Published by the American Physical Society