Measurement of Branching Fractions of Singly Cabibbo-suppressed Decays $\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^0{K}^{+}$ and $\hat{I}{\pounds }^{+}{K}_S^0$

Abstract

Based on a sample of 4.4 ${\mathrm{fb}}^{-1}$ of $e^{+}{e}^{-}$ annihilation data collected in the energy region between 4.6 GeV and 4.7 GeV with the BESIII detector at BEPCII, two singly Cabibbo-suppressed decays $\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^0{K}^{+}$ and $\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^{+}{K}_S^0$ are studied. The ratio of the branching fraction $\mathcal{B}(\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^0{K}^{+})$ relative to $\mathcal{B}(\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^0\ddot{I}{€}^{+})$ is measured to be $0.0361\pm 0.0073(stat.)\pm 0.0005(syst.)$, and the ratio of $\mathcal{B}(\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^{+}{K}_S^0)$ relative to $\mathcal{B}(\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^{+}\ddot{I}{€}^{+}\ddot{I}{€}^{-})$ is measured to be $0.0106\pm 0.0031(stat.)\pm 0.0004(syst.)$. After taking the world-average branching fractions of the reference decay channels, the branching fractions $\mathcal{B}(\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^0{K}^{+})$ and $\mathcal{B}(\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^{+}{K}_S^0)$ are determined to be $(4.7\pm 0.9(stat.)\pm 0.1(syst.)\pm 0.3(ref.))\times 10^{-4}$ and $(4.8\pm 1.4(stat.)\pm 0.2(syst.)\pm 0.3(ref.))\times 10^{-4}$, respectively. The branching fraction of the $\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^{+}{K}_S^0$ decay is measured for the first time.

13 pages, 4 figures