Analysis of the $P_c(4380)$ and $P_c(4450)$ as pentaquark states in the diquark model with QCD sum rules

Abstract

In this article, we construct the diquark-diquark-antiquark type interpolating currents, and study the masses and pole residues of the $J^P={\frac{3}{2}}^{-}$ and ${\frac{5}{2}}^{+}$ hidden-charmed pentaquark states in details with the QCD sum rules by calculating the contributions of the vacuum condensates up to dimension-10 in the operator product expansion. In calculations, we use the formula $\mu =\sqrt{M_{P_c}^2-(2{\mathbb{M}}_c{)}^2}$ to determine the energy scales of the QCD spectral densities. The present predictions favor assigning the $P_c(4380)$ and $P_c(4450)$ to be the ${\frac{3}{2}}^{-}$ and ${\frac{5}{2}}^{+}$ pentaquark states, respectively.

Comments: 18 pages, 5 figures