Amplitude analysis of the ${K}_{S}{K}_{S}$ system produced in radiative $J/\psi $ decays

An amplitude analysis of the ${K}_{S}{K}_{S}$ system produced in radiative $J/\psi $ decays is performed using the $\left(1310.6±7.0\right)×{10}^{6}\text{}\text{}J/\psi $ decays collected by the BESIII detector. Two approaches are presented. A mass-dependent analysis is performed by parametrizing the ${K}_{S}{K}_{S}$ invariant mass spectrum as a sum of Breit-Wigner line shapes. Additionally, a mass-independent analysis is performed to extract a piecewise function that describes the dynamics of the ${K}_{S}{K}_{S}$ system while making minimal assumptions about the properties and number of poles in the amplitude. The dominant amplitudes in the mass-dependent analysis include the ${f}_{0}\left(1710\right)$, ${f}_{0}\left(2200\right)$, and ${f}_{2}^{\prime }\left(1525\right)$. The mass-independent results, which are made available as input for further studies, are consistent with those of the mass-dependent analysis and are useful for a systematic study of hadronic interactions. The branching fraction of radiative $J/\psi $ decays to ${K}_{S}{K}_{S}$ is measured to be $\left(8.1±0.4\right)×{10}^{-4}$, where the uncertainty is systematic and the statistical uncertainty is negligible.