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

Abstract

In this work, we systematically investigate the singly-charmed pentaquark molecular states $D^{(*)}N$, $D^{(*)}Ξ^{(*)}$ and $D_s^{(*)}Ξ^{(*)}$ 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 $Ω_c(3185)$ as the $DΞ$ molecular state with the $J^P=\frac{1}{2}^-$ and $| I,I_3 \rangle=| 0,0 \rangle$, assigning the $Ω_c(3327)$ as the $D^*Ξ$ molecular state with the $J^P=\frac{3}{2}^-$ and $|I,I_3 \rangle=| 0,0 \rangle$, assigning the $Σ_c(2800)$ as the $DN$ molecular state with the $J^P=\frac{1}{2}^-$ and $| I,I_3 \rangle=| 1,0 \rangle$, and assigning the $Λ_c(2940)/Λ_c(2910)$ as the $D^*N$ molecular state with the $J^P=\frac{3}{2}^-$ and $| I,I_3 \rangle=| 0,0 \rangle$. Other potential molecule candidates are also predicted, which may be observed in future experiments. For example, we can search for the $DΞ$ and $D^*Ξ$ molecular states with the isospin $| I,I_3 \rangle=| 1,\pm1 \,\rangle$ in the $Ξ_c^+\bar{K}^0$ and $Ξ_c^0\bar{K}^-$ mass spectrum respectively in the future, which could shed light on the nature of the $Ω_c(3185/3327)$.