First Observation of \boldmath{$D^{+}\to a_0(980)\ddot{I}$ and $D^{+}\to a_0(980{)}^{+}{f}_0(500)$} in \boldmath{$D^{+}\to \ddot{I}{€}^{+}\ddot{I}{€}^{+}\ddot{I}{€}^{-}\hat{I}\cdot$ and $D^{+}\to \ddot{I}{€}^{+}\ddot{I}{€}^0\ddot{I}{€}^0\hat{I}\cdot$} Decays

BESIII Collaboration, M. Ablikim, M. N. Achasov +756

We perform the first amplitude analysis of the singly Cabibbo-suppressed decays $D^{+}\to \ddot{I}{€}^{+}\ddot{I}{€}^{+(0)}\ddot{I}{€}^{-(0)}\hat{I}\cdot$, using $e^{+}{e}^{-}$ collision data collected with the BESIII detec…