Evidence for a Neutral Near-Threshold Structure in the ${K}_{S}^{0}$ Recoil-Mass Spectra in ${e}^{+}{e}^{-}\to {K}_{S}^{0}{D}_{s}^{+}{D}^{*-}$ and ${e}^{+}{e}^{-}\to {K}_{S}^{0}{D}_{s}^{*+}{D}^{-}$

We study the processes ${e}^{+}{e}^{-}\to {K}_{S}^{0}{D}_{s}^{+}{D}^{*-}$ and ${e}^{+}{e}^{-}\to {K}_{S}^{0}{D}_{s}^{*+}{D}^{-}$, as well as their charge conjugated processes, at five center-of-mass energies between 4.628 and 4.699 GeV, using data samples corresponding to an integrated luminosity of $3.8\text{}\text{}{\mathrm{fb}}^{-1}$ collected by the BESIII detector at the BEPCII storage ring. Based on a partial reconstruction technique, we find evidence of a structure near the thresholds for ${D}_{s}^{+}{D}^{*-}$ and ${D}_{s}^{*+}{D}^{-}$ production in the ${K}_{S}^{0}$ recoil-mass spectrum, which we refer to as the ${Z}_{cs}\left(3985{\right)}^{0}$. Fitting with a Breit-Wigner line shape, we find the mass of the structure to be $\left(3992.2±1.7±1.6\right)\text{}\text{}\mathrm{MeV}/{c}^{2}$ and the width to be $\left(7.{7}_{-3.8}^{+4.1}±4.3\right)\text{}\text{}\mathrm{MeV}$, where the first uncertainties are statistical and the second are systematic. The significance of the ${Z}_{cs}\left(3985{\right)}^{0}$ signal is found to be $4.6\sigma $ including both the statistical and systematic uncertainty. We report the Born cross section multiplied by the branching fraction at different energy points. The mass of the ${Z}_{cs}\left(3985{\right)}^{0}$ is close to that of the ${Z}_{cs}\left(3985{\right)}^{+}$. Assuming SU(3) symmetry, the cross section of the neutral channel is consistent with that of the charged one. Hence, we conclude that the ${Z}_{cs}\left(3985{\right)}^{0}$ is the isospin partner of the ${Z}_{cs}\left(3985{\right)}^{+}$.