Study of the doubly Cabibbo-suppressed decays $D_s^{+}\to K^{+}{K}^{+}\ddot{I}{€}^{-}$ and $D_s^{+}\to K^{+}{K}^{+}\ddot{I}{€}^{-}\ddot{I}{€}^0$

Abstract

Based on 7.33 fb${}^{-1}$ of $e^{+}{e}^{-}$ collision data collected at center-of-mass energies between 4.128 and 4.226 GeV with the BESIII detector, the experimental studies of the doubly Cabibbo-suppressed decays $D_s^{+}\to K^{+}{K}^{+}\ddot{I}{€}^{-}$ and $D_s^{+}\to K^{+}{K}^{+}\ddot{I}{€}^{-}\ddot{I}{€}^0$ are reported. We determine the absolute branching fraction of $D_s^{+}\to K^{+}{K}^{+}\ddot{I}{€}^{-}$ to be ($1.23_{-0.25}^{+0.28}(\mathrm{stat})\pm 0.06(\mathrm{syst})$) $\times 10^{-4}$. No significant signal of $D_s^{+}\to K^{+}{K}^{+}\ddot{I}{€}^{-}\ddot{I}{€}^0$ is observed and the upper limit on its decay branching fraction at 90\% confidence level is set to be $1.7\times 10^{-4}$.

10 pages, 4 figures, 4 tables