Amplitude analysis and branching-fraction measurement of $D_s^{+}\to \ddot{I}{€}^{+}\ddot{I}{€}^0\hat{I}{\cdot }^{\prime }$

Abstract

Using data collected with the BESIII detector in $e^{+}{e}^{-}$ collisions at center-of-mass energies between 4.178 and 4.226 GeV and corresponding to 6.32~fb${}^{-1}$ of integrated luminosity, we report the amplitude analysis and branching-fraction measurement of the $D_s^{+}\to \ddot{I}{€}^{+}\ddot{I}{€}^0\hat{I}{\cdot }^{\prime }$ decay. We find that the dominant intermediate process is $D_s^{+}\to \ddot{I}{}^{+}\hat{I}{\cdot }^{\prime }$ and the significances of other resonant and nonresonant processes are all less than $3\ddot{I}ƒ$. The upper limits on the branching fractions of $S$-wave and $P$-wave nonresonant components are set to $0.10\%$ and $0.74\%$ at the $90\%$ confidence level, respectively. In addition, the branching fraction of the $D_s^{+}\to \ddot{I}{€}^{+}\ddot{I}{€}^0\hat{I}{\cdot }^{\prime }$ decay is measured to be $(6.15\pm 0.25(stat.)\pm 0.18(syst.))\%$, which receives significant contribution only from $D_s^{+}\to \ddot{I}{}^{+}\hat{I}{\cdot }^{\prime }$ according to the amplitude analysis.