Improved measurement of the branching fractions of the inclusive decays ${D}^{+}\to {K}_{S}^{0}X$ and ${D}^{0}\to {K}_{S}^{0}X$

By analyzing $2.93\text{}\text{}{\mathrm{fb}}^{-1}$ of ${e}^{+}{e}^{-}$ collision data taken at the center-of-mass energy of 3.773 GeV with the BESIII detector, the branching fractions of the inclusive decays ${D}^{+}\to {K}_{S}^{0}X$ and ${D}^{0}\to {K}_{S}^{0}X$ are measured to be $\left(33.11±0.13±0.36\right)%$ and $\left(20.75±0.12±0.20\right)%$, respectively, where the first uncertainties are statistical and the second are systematic. These results are consistent with the world averages of previous measurements, but with much improved precision.