New structure around 3250 MeV in the baryonic B decay and the $D_0^{\ast }(2400)N$ molecular hadron

In this work, we first propose the isovector $n{D}_0^{\ast }(2400{)}^0$ molecular state to explain the enhancement structure around 3250 MeV ($X_c(3250{)}^0$) in the ${\mathrm{\Sigma }}_c^{++}{\pi }^{-}{\pi }^{-}$ invariant mass spectrum newly observed by the BaBar Collaboration. Under this molecular state configuration, both the analysis of the mass spectrum and the study of its dominant decay channel can well depict its resonance parameters measured by BaBar. Our investigation also shows that the isovector $n{D}_0^{\ast }(2400{)}^0$ molecular state can decay into ${\mathrm{\Sigma }}_c^{++}{\pi }^{-}{\pi }^{-}$, which is consistent with the experimental observation. These studies provide the direct support to the isovector $n{D}_0^{\ast }(2400{)}^0$ molecular state assignment to $X_c(3250{)}^0$.