Establishing the first hidden-charm pentaquark with strangeness

TL;DR

This paper uses QCD sum rules to analyze the $P_{cs}(4459)^0$ pentaquark, supporting its interpretation as a hadronic molecular state and proposing further experimental investigations to confirm its structure.

Contribution

It provides the first theoretical analysis of the $P_{cs}(4459)^0$ as a hidden-charm pentaquark with strangeness using QCD sum rules, supporting the molecular state hypothesis.

Findings

Supports $P_{cs}(4459)^0$ as a $ar D^* \xi_c$ molecular state

Suggests $P_{cs}(4459)^0$ can be split into two states

Proposes searching for $ar D \xi_c$ molecular state

Abstract

We study the $P_{cs}(4459)^0$ recently observed by LHCb using the method of QCD sum rules. Our results support its interpretation as the $\bar D^* \Xi_c$ hadronic molecular state of either $J^P=1/2^-$ or $3/2^-$. Within the hadronic molecular picture, the three LHCb experiments observing $P_c$ and $P_{cs}$ states \cite{lhcb,Aaij:2015tga,Aaij:2019vzc} can be well understood as a whole. This strongly supports the existence of hadronic molecules, whose studies can significantly improve our understanding on the construction of the subatomic world. To verify this picture, we propose to further investigate the $P_{cs}(4459)^0$ to examine whether it can be separated into two states, and to search for the $\bar D \Xi_c$ molecular state of $J^P=1/2^-$.