Anticharmed strange pentaquarks from the one-boson-exchange model

Abstract

Inspired by the LHCb's discovery of hidden-charm pentaquarks, the anticharmed strange pentaquarks $P_{\bar c s}$ in a favor of the hadronic molecule picture are investigated from the one-boson-exchange model. Similar to the hidden-charm pentaquarks, three molecular bound states, one with spin parity $J^P=1/2^-$ below the $\bar D\Sigma$ threshold and another two with $J^P=\{1/2^-,3/2^-\}$ below the $\bar D^*\Sigma$ threshold, are predicted at $3-3.2$ GeV mass region. The mass ordering of the later two states can be interchanged by different reductions of the $\delta(r)$ term. Furthermore, resonances associated with these three bound states are examined by considering $ D_s^-N-\bar D\Lambda-\bar D \Sigma-\bar D^*\Lambda-\bar D^*\Sigma$ coupled-channel dynamics, and decay widths of them are predicted. Our study indicates that the $ D_s^- p$ invariant mass spectrum in the $\bar B_s^0\to \bar n D_s^- p$ decay is an appropriate place to detect the $P_{\bar c s}$ pentaquarks.