Study of the decay $D^{+}\to K^{\ast }(892{)}^{+}{K}_S^0$ in $D^{+}\to K^{+}{K}_S^0\ddot{I}{€}^0$

Abstract

Based on an $e^{+}{e}^{-}$ collision data sample corresponding to an integrated luminosity of 2.93 ${\mathrm{fb}}^{-1}$ collected with the BESIII detector at $\sqrt{s}=3.773\mathrm{GeV}$, the first amplitude analysis of the singly Cabibbo-suppressed decay $D^{+}\to K^{+}{K}_S^0\ddot{I}{€}^0$ is performed. From the amplitude analysis, the $K^{\ast }(892{)}^{+}{K}_S^0$ component is found to be dominant with a fraction of $(57.1\pm 2.6\pm 4.2)\%$, where the first uncertainty is statistical and the second systematic. In combination with the absolute branching fraction $\mathcal{B}(D^{+}\to K^{+}{K}_S^0\ddot{I}{€}^0)$ measured by BESIII, we obtain $\mathcal{B}(D^{+}\to K^{\ast }(892{)}^{+}{K}_S^0)=(8.69\pm 0.40\pm 0.64\pm 0.51)\times 10^{-3}$, where the third uncertainty is due to the branching fraction $\mathcal{B}(D^{+}\to K^{+}{K}_S^0\ddot{I}{€}^0)$. The precision of this result is significantly improved compared to the previous measurement.

12 pages, 15 figures