Measurement of the absolute branching fraction of the three-body decay $\hat{I}{›}_c^{+}\to \hat{I}{ž}^0{K}^{+}\ddot{I}{€}^0$ and search for $\hat{I}{›}_c^{+}\to n{K}^{+}\ddot{I}{€}^0$, $\hat{I}{\pounds }^0{K}^{+}\ddot{I}{€}^0$ and $\hat{I}›K^{+}\ddot{I}{€}^0$

Abstract

The Cabbibo-favored decay $\hat{I}{›}_c^{+}\to \hat{I}{ž}^0{K}^{+}\ddot{I}{€}^0$ is studied for the first time using 6.1 fb${}^{-1}$ of $e^{+}{e}^{-}$ collision data at center-of-mass energies between 4.600 and 4.840 GeV, collected with the BESIII detector at the BEPCII collider. With a double-tag method, the branching fraction of the three-body decay $\hat{I}{›}_c^{+}\to \hat{I}{ž}^0{K}^{+}\ddot{I}{€}^0$ is measured to be $(7.79\pm 1.46_{}\pm 0.71_{})\times 10^{-3}$, where the first and second uncertainties are statistical and systematic, respectively. The branching fraction of the two-body decay $\hat{I}{›}_c^{+}\to \hat{I}ž(1530{)}^0{K}^{+}$ is $(5.99\pm 1.04\pm 0.29)\times 10^{-3}$, which is consistent with the previous result of $(5.02\pm 0.99\pm 0.31)\times 10^{-3}$. In addition, the upper limit on the branching fraction of the doubly Cabbibo-suppressed decay $\hat{I}{›}_c^{+}\to n{K}^{+}\ddot{I}{€}^0$ is $7.1\times 10^{-4}$ at the 90$\%$ confidence level. The upper limits on the branching fractions of $\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^0{K}^{+}\ddot{I}{€}^0$ and $\hat{I}›K^{+}\ddot{I}{€}^0$ are also determined to be $1.8\times 10^{-3}$ and $2.0\times 10^{-3}$, respectively.

15 pages, 20 figures