Measurement of cross sections of $e^{+}{e}^{-}\to K_S^0{K}_S^0\psi (3686)$ from $\sqrt{s}=$ 4.682 to 4.951 GeV

Abstract

The process $e^{+}{e}^{-}\to K_S^0{K}_S^0\psi (3686)$ is studied by analyzing $e^{+}{e}^{-}$ collision data samples collected at eight center-of-mass energies ranging from 4.682 to 4.951 GeV with the BESIII detector operating at the BEPCII collider, corresponding to an integrated luminosity of $4.1{\mathrm{fb}}^{-1}$. Observation of the $e^{+}{e}^{-}\to K_S^0{K}_S^0\psi (3686)$ process is found for the first time with a statistical significance of $6.3\sigma$, and the cross sections at each center-of-mass energy are measured. The ratio of cross sections of $e^{+}{e}^{-}\to K_S^0{K}_S^0\psi (3686)$ relative to $e^{+}{e}^{-}\to K^{+}{K}^{-}\psi (3686)$ is determined to be $\frac{\sigma (e^{+}{e}^{-}\to K_S^0{K}_S^0\psi (3686))}{\sigma (e^{+}{e}^{-}\to K^{+}{K}^{-}\psi (3686))}=0.45\pm 0.25$, which is consistent with the prediction based on isospin symmetry. The uncertainty includes both statistical and systematic contributions. Additionally, the $K_S^0\psi (3686)$ invariant mass distribution is found to be consistent with three-body phase space. The significance of a contribution beyond three-body phase space is only $0.8\sigma$.