Measurements of branching fractions of $\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^0{K}_S^0\ddot{I}{€}^{+}$ and $\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^0{K}_S^0{K}^{+}$

Abstract

Based on a data sample corresponding to an integrated luminosity of 6.4~fb${}^{-1}$ of $e^{+}{e}^{-}$ annihilation and collected with the BESIII detector at 13 center-of-mass energy points ranging between 4.600~GeV and 4.950~GeV, we report the first observation of the singly Cabibbo-suppressed decay $\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^0{K}_S^0\ddot{I}{€}^{+}$ with a statistical significance of 5.9$\ddot{I}ƒ$. The branching fraction is determined to be $\mathcal{B}(\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^0{K}_S^0\ddot{I}{€}^{+})=(0.58\pm 0.14_{stat.}\pm 0.04_{syst.})\times 10^{-3}$. In addition, the decay $\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^0{K}_S^0{K}^{+}$ has also been investigated, and the first evidence for this decay is obtained with a statistical significance of 3.7$\ddot{I}ƒ$.