Strong decay mode $J/\psi p$ of hidden charm pentaquark states $P_c^{+}(4380)$ and $P_c^{+}(4450)$ in ${\Sigma }_c{\bar{D}}^{\ast }$ molecular scenario

Abstract

We study the strong decay channels $P_c^{+}(4380)\to J/\psi p$ and $P_c^{+}(4450)\to J/\psi p$ under ${\Sigma }_c{\bar{D}}^{\ast }$ molecular state ansatz. With various spin-parity assignments, the partial decay widths of $J/\psi p$ final state are calculated. Our results show that all the $P$ wave ${\Sigma }_c{\bar{D}}^{\ast }$ assignments are excluded, while $S$ wave ${\Sigma }_c{\bar{D}}^{\ast }$ pictures for $P_c(4380)$ and $P_c(4450)$ are both allowed by present experimental data. The $J^P=3/2^{-}$ ${\Sigma }_c^{\ast }\bar{D}$ and ${\Sigma }_c^{\ast }{\bar{D}}^{\ast }$ molecules are also discussed in the heavy quark limit, and find that the ${\Sigma }_c^{\ast }\bar{D}$ system for $P_c(4380)$ is possible. More experimental information on spin-parities and partial decay widths and theoretical investigations on other decay modes are needed to clarify the nature of the two $P_c$ states.

Comments: 7 pages, 6 figures, 2 tables. More discussions are added. Version accepted by Phys. Rev. D