Hidden charm pentaquark states and $\Sigma_c^{(*)}\bar{D}^{(*)}$ interaction in chiral perturbation theory

TL;DR

This paper uses chiral perturbation theory to analyze the interactions between certain charm baryons and mesons, reproducing known pentaquark states and exploring new effects from loop diagrams.

Contribution

It provides a next-to-leading order calculation of $ ext{Σ}_c^{(*)}ar{ ext{D}}^{(*)}$ interactions including coupled-channel effects, advancing the molecular understanding of pentaquark states.

Findings

Reproduces three $P_c$ states as molecular states.

Includes coupled-channel effects in the interaction.

Discusses novel effects from loop diagrams.

Abstract

We adopt the chiral perturbation theory to calculate the $\Sigma_{c}^{(*)}\bar{D}^{(*)}$ interaction to the next-to-leading order (NLO) and include the couple-channel effect in the loop diagrams. We reproduce the three $P_c$ states in the molecular picture after including the $\Lambda_{c}\bar{D}^{(*)}$ intermediate states. We also discuss some novel observations arising from the loop diagrams.