$\bar{D}\Sigma^*_c$ and $\bar{D}^*\Sigma_c$ interactions and the LHCb hidden-charmed pentaquarks

TL;DR

This paper investigates the interactions between specific meson-baryon pairs and suggests that the observed pentaquark states $P_c(4380)$ and $P_c(4450)$ are likely molecular states formed from these interactions, supported by dynamical calculations.

Contribution

It provides a dynamical model showing that the $P_c(4380)$ and $P_c(4450)$ can be explained as molecular states from $ar{D}\Sigma_c^*$ and $ar{D}^*\Sigma_c$ interactions, respectively.

Findings

A bound state with $J^P=3/2^-$ from $ar{D}\Sigma_c^*(2520)$ matches $P_c(4380)$.

A bound state with $J^P=5/2^+$ from $D^*\Sigma_c(2455)$ matches $P_c(4450)$.

Supports the molecular interpretation of the $P_c$ states.

Abstract

Very recently, two hidden-charmed resonances $P_c(4380)$ and $P_c(4450)$ consistent with pentaquark states were observed at the LHCb detector. The two $P_c$ states locate just below the $\bar{D}\Sigma^*_c$ and $\bar{D}^*\Sigma_c$ thresholds with mass of gaps about 5 and 15 MeV, respectively. Inspired by this fact we perform a dynamical investigation about the $\bar{D}\Sigma_c^*(2520)$ and $\bar{D}^*\Sigma_c(2455)$ interactions which are described by the meson exchanges. A bound state which carries spin-parity $J^P=3/2^-$ is produced from the $\bar{D}\Sigma^*_c(2520)$ interaction, which is consistent with the $P_c(4380)$ observed at the LHCb detector. From the $D^*\Sigma_c(2455)$ interaction, a bound state with $5/2^+$ is produced, which can be related to the $P_c(4450)$. The results suggest that the $P_c(4380)$ and $P_c(4450)$ are good candidates of $\bar{D}\Sigma_c^*(2520)$ and $\bar{D}^*\Sigma_c(2455)$ molecular states, respectively.