Amplitude analysis and branching fraction measurement of the decay $D_s^{+}\to \ddot{I}{€}^{+}\ddot{I}{€}^0\ddot{I}{€}^0$

Abstract

Using a data set corresponding to an integrated luminosity of 6.32~$\mathrm{f}{\mathrm{b}}^{-1}$ recorded by the BESIII detector at center-of-mass energies between 4.178 and 4.226~GeV, an amplitude analysis of the decay $D_s^{+}\to \ddot{I}{€}^{+}\ddot{I}{€}^0\ddot{I}{€}^0$ is performed, and the relative fractions and phases of different intermediate processes are determined. The absolute branching fraction of the decay $D_s^{+}\to \ddot{I}{€}^{+}\ddot{I}{€}^0\ddot{I}{€}^0$ is measured to be $(0.50\pm 0.04_{\text{stat}}\pm 0.02_{\text{syst}})\%$. The absolute branching fraction of the intermediate process $D_s^{+}\to f_0(980)\ddot{I}{€}^{+},f_0(980)\to \ddot{I}{€}^0\ddot{I}{€}^0$ is determined to be $(0.21\pm 0.03_{\text{stat}}\pm 0.03_{\text{syst}})\%$.