Quark model estimate of hidden-charm pentaquark resonances

TL;DR

This study uses a quark model with explicit channel coupling to investigate hidden-charm pentaquark resonances, finding no evidence for known states but identifying new potential resonances at higher energies.

Contribution

It applies a comprehensive quark model with coupled channels and advanced methods to analyze pentaquark resonances, providing new insights into their possible existence and properties.

Findings

No resonance at P_c(4380) and P_c(4450) energies

Resonant states identified at 4690 MeV and 4920 MeV

Discovered compact structures with specific quantum numbers

Abstract

A quark model, which reproduces the ground-state mesons and baryons, i.e., the threshold energies, is applied to the $qqqc\bar c$ configurations, where $q$ is a light quark and~$c$ the charmed quark. In the calculation, several open channels are explicitly included such as $\Jpsi +N$, $\eta_c+N$, $\Lambda_c +D$, etc. To distinguish genuine resonances and estimate their width, we employ Gaussian Expansion Method supplemented by the real scaling method (stabilization). No resonance is found at the energies of the $P_c(4380)$ and $P_c(4450)$ pentaquarks. On the other hand, there is a sharp resonant state at 4690\,MeV with $J=1/2^-$ state and another one at 4920\,MeV with $J=3/2^-$ state, which have a compact structure.