Observation of an Altered $a_0(980)$ Line-shape in $D^{+}\to {\pi }^{+}\eta \eta$ due to the Triangle Loop Rescattering Effect

BESIII Collaboration, M. Ablikim, M. N. Achasov +697

Using 20.3~${\mathrm{fb}}^{-1}$ of $e^{+}{e}^{-}$ collision data taken with the BESIII detector at the center-of-mass energy 3.773~GeV, we report the first amplitude analysis of the hadro…