Observation of the decay $D_s^{+}\to \ddot{I}‰\ddot{I}{€}^{+}\hat{I}\cdot$

Abstract

Using 7.33 fb${}^{-1}$ of $e^{+}{e}^{-}$ collision data collected by the BESIII detector at center-of-mass energies between 4.128 and 4.226~GeV, we observe for the first time the decay $D_s^{\pm }\to \ddot{I}‰\ddot{I}{€}^{\pm }\hat{I}\cdot$ with a statistical significance of 7.6$\ddot{I}ƒ$. The measured branching fraction of this decay is $(0.54\pm 0.12\pm 0.04)\%$, where the first uncertainty is statistical and the second is systematic.