Measurement of Singly Cabibbo Suppressed Decays $\hat{I}{›}_c^{+}\to p\ddot{I}{€}^{+}\ddot{I}{€}^{-}$ and $\hat{I}{›}_c^{+}\to p{K}^{+}{K}^{-}$

Abstract

Using 567 $p{b}^{-1}$ of data collected with the BESIII detector at a center-of-mass energy of $\sqrt{s}=$ 4.599 $GeV$, near the $\hat{I}{›}_c^{+}\hat{I}{›}_c^{-}$ threshold, we study the singly Cabibbo-suppressed decays $\hat{I}{›}_c^{+}\to p\ddot{I}{€}^{+}\ddot{I}{€}^{-}$ and $\hat{I}{›}_c^{+}\to p{K}^{+}{K}^{-}$. By normalizing with respect to the Cabibbo-favored decay $\hat{I}{›}_c^{+}\to p{K}^{-}\ddot{I}{€}^{+}$, we obtain ratios of branching fractions: $\frac{\mathcal{B}(\hat{I}{›}_c^{+}\to p\ddot{I}{€}^{+}\ddot{I}{€}^{-})}{\mathcal{B}(\hat{I}{›}_c^{+}\to p{K}^{-}\ddot{I}{€}^{+})}$ = $(6.70\pm 0.48\pm 0.25)\%$, $\frac{\mathcal{B}(\hat{I}{›}_c^{+}\to p\ddot{I}•)}{\mathcal{B}(\hat{I}{›}_c^{+}\to p{K}^{-}\ddot{I}{€}^{+})}$ = $(1.81\pm 0.33\pm 0.13)\%$, and $\frac{\mathcal{B}(\hat{I}{›}_c^{+}\to p{K}^{+}{K}_{\text{non-}\ddot{I}•}^{-})}{\mathcal{B}(\hat{I}{›}_c^{+}\to p{K}^{-}\ddot{I}{€}^{+})}$ = $(9.36\pm 2.22\pm 0.71)\times 10^{-3}$, where the uncertainties are statistical and systematic, respectively. The absolute branching fractions are also presented. Among these measurements, the decay $\hat{I}{›}_c^{+}\to p\ddot{I}{€}^{+}\ddot{I}{€}^{-}$ is observed for the first time, and the precision of the branching fraction for $\hat{I}{›}_c^{+}\to p{K}^{+}{K}_{\text{non-}\ddot{I}•}^{-}$ and $\hat{I}{›}_c^{+}\to p\ddot{I}•$ is significantly improved.