The singly-charmed pentaquark molecular states via the QCD sum rules

Abstract

In this work, we systematically investigate the singly-charmed pentaquark molecular states $D^{(\ast )}N$, $D^{(\ast )}{\Xi }^{(\ast )}$ and $D_s^{(\ast )}{\Xi }^{(\ast )}$ with the QCD sum rules by carrying out the operator product expansion up to the vacuum condensates of dimension 13 and taking fully account of the light-flavor $SU(3)$ breaking effects. The numerical results favor assigning the ${\Omega }_c(3185)$ as the $D\Xi$ molecular state with the $J^P={\frac{1}{2}}^{-}$ and $|I,I_3⟩=|0,0⟩$, assigning the ${\Omega }_c(3327)$ as the $D^{\ast }\Xi$ molecular state with the $J^P={\frac{3}{2}}^{-}$ and $|I,I_3⟩=|0,0⟩$, assigning the ${\Sigma }_c(2800)$ as the $DN$ molecular state with the $J^P={\frac{1}{2}}^{-}$ and $|I,I_3⟩=|1,0⟩$, and assigning the ${\Lambda }_c(2940)/{\Lambda }_c(2910)$ as the $D^{\ast }N$ molecular state with the $J^P={\frac{3}{2}}^{-}$ and $|I,I_3⟩=|0,0⟩$. Other potential molecule candidates are also predicted, which may be observed in future experiments. For example, we can search for the $D\Xi$ and $D^{\ast }\Xi$ molecular states with the isospin $|I,I_3⟩=|1,\pm 1⟩$ in the ${\Xi }_c^{+}{\bar{K}}^0$ and ${\Xi }_c^0{\bar{K}}^{-}$ mass spectrum respectively in the future, which could shed light on the nature of the ${\Omega }_c(3185/3327)$.

Comments: 23 pages, 6 figures