Rich structure of the hidden-charm pentaquarks near threshold regions

Abstract

The recent discoveries and observations of pentaquarks and tetraquarks by high-energy accelerator facilities have accumulated evidence of the existence of multiquark hadrons with heavy quarks, as discussed from the early stage of the prediction of quarks. We construct a coupled-channel model for the hidden-charm pentaquarks with strangeness whose quark content is $udsc\overline{c}$, ${P}_{cs}$, described as ${\mathrm{\ensuremath{\Lambda}}}_{c}{\overline{D}}_{s}^{(*)}$, ${\mathrm{\ensuremath{\Xi}}}_{c}^{{(}^{\ensuremath{'}}*)}{\overline{D}}^{(*)}$ molecules, produced by the cooperation of the heavy quark and chiral symmetries, coupled to a five-quark core. We reproduce the experimental mass of ${P}_{cs}$, of which LHCb has announced the discovery. Furthermore, our result supports the quantum numbers that are preferred by the experiment. Our predictions indicate the existence of additional ${P}_{cs}$'s in proximity to molecular threshold regions, which can be further investigated by LHCb.