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The LHCb collaboration has recently announced the discovery of two
hidden-charm pentaquark states with also strange quark content, $P_{cs}(4338)$
and $P_{cs}(4459)$; its analysis points towards having both hadrons isospin
equal to zero and spin-parity quantum numbers $\frac12^-$ and $\frac32^-$,
respectively. We perform herein a systematical investigation of the
$qqsc\bar{c}$ $(q=u,\,d)$ system by means of a chiral quark model, along with a
highly accurate computational method, the Gaussian expansion approach combined
with the complex-scaling technique. Baryon-meson configurations in both
singlet- and hidden-color channels are considered. The $P_{cs}(4338)$ and
$P_{cs}(4459)$ signals can be well identified as molecular bound states with
dominant components $\Lambda J/\psi$ $(60\%)$ and $\Xi_c D$ $(23\%)$ for the
lowest-energy case and $\Xi_c D^*$ $(72\%)$ for the highest-energy one.
Besides, it seems that some narrow resonances can be also found in each allowed
$I(J^P)$-channel in the energy region of $4.6-5.5$ GeV, except for the
$1(\frac12^-)$ where a shallow bound state with dominant $\Xi^*_c D^*$
structure is obtained at $4673$ MeV with binding energy $E_B=-3$ MeV. These
exotic states are expected to be confirmed in future high energy experiments.
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