The $Z_c(3900)$ peak does not come from the triangle singularity

We compare contributions from the triangle diagram and the $Dbar D^*$ bubble chain to the processes of $e^{+}e^{-}rightarrow J/psipi^{+}pi^{-}$ and $e^{+}e^{-}rightarrow (Dbar D^*)^mppi^{pm}$. By fitting the $J/psipi$ maximum spectrum and the $Dbar D^*$ spectrum, we find that the triangle diagram cannot explain the new data from BESIII Collaboration at center of mass at 4.23GeV and 4.26GeV, simultaneously. On the contrary, the molecular assignment of $Z_c(3900)$ gives a much better description.