Measurements of the branching fractions for $D^{+}\to K_S^0{K}_S^0{K}^{+}$, $K_S^0{K}_S^0\ddot{I}{€}^{+}$ and $D^0\to K_S^0{K}_S^0$, $K_S^0{K}_S^0{K}_S^0$

Abstract

By analyzing $2.93\mathrm{f}{\mathrm{b}}^{-1}$ of data taken at the $\ddot{I}ˆ(3770)$ resonance peak with the BESIII detector, we measure the branching fractions for the hadronic decays $D^{+}\to K_S^0{K}_S^0{K}^{+}$, $D^{+}\to K_S^0{K}_S^0\ddot{I}{€}^{+}$, $D^0\to K_S^0{K}_S^0$ and $D^0\to K_S^0{K}_S^0{K}_S^0$. They are determined to be $\mathcal{B}(D^{+}\to K_S^0{K}_S^0{K}^{+})=(2.54\pm 0.05_{stat.}\pm 0.12_{sys.})\times 10^{-3}$, $\mathcal{B}(D^{+}\to K_S^0{K}_S^0\ddot{I}{€}^{+})=(2.70\pm 0.05_{stat.}\pm 0.12_{sys.})\times 10^{-3}$, $\mathcal{B}(D^0\to K_S^0{K}_S^0)=(1.67\pm 0.11_{stat.}\pm 0.11_{sys.})\times 10^{-4}$ and $\mathcal{B}(D^0\to K_S^0{K}_S^0{K}_S^0)=(7.21\pm 0.33_{stat.}\pm 0.44_{sys.})\times 10^{-4}$, where the second one is measured for the first time and the others are measured with significantly improved precision over the previous measurements.

9 pages, 4 figures