Dynamical study of hidden-strange pentaquarks as analogs of the hidden-charm states

TL;DR

This paper theoretically investigates hidden-strange pentaquarks using the QDCSM and RGM, predicting bound states and a resonance that can guide future experimental searches.

Contribution

It introduces a systematic study of hidden-strange pentaquarks with novel predictions of bound states and resonances, emphasizing the role of channel coupling effects.

Findings

Predicted three bound states at 1759, 2000, and 2407 MeV.

Identified a hidden-strange pentaquark resonance at 2204-2208 MeV.

Estimated the total decay width of the resonance as 55-63 MeV.

Abstract

Motivated by the recent BESIII experiment~\cite{BESIII:2024muk} searching for hidden-strange exotic hadrons, we perform a systematic theoretical study of the hidden-strange pentaquark system within the framework of the quark delocalization color screening model (QDCSM) and the resonating group method (RGM). Our results demonstrate that the channel coupling effect plays a decisive role in the formation of bound and resonance states. It not only significantly enhances the short-range attraction but also induces essential attractive contributions from pion exchange. We predict three bound states with masses of $1759$ MeV, $2000$ MeV, and $2407$ MeV. Furthermore, we report the existence of a hidden-strange pentaquark resonance state, $\Xi K^{\ast}$, with quantum numbers $I(J^{P})=0(1/2^{-})$. This resonance is identified in the $S$-wave scattering phase shifts of the $\Lambda\eta_{s}$ and $\Lambda \phi$ open channels, with a predicted mass in the range of $2204\text{--}2208$ MeV. By accounting for both the scattering width from channel coupling and the intrinsic decay width of the constituent $K^{\ast}$, the total decay width is estimated to be $55\text{--}63$ MeV. These theoretical predictions provide important guidance for future experimental searches for such exotic states at facilities like BESIII.