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 ${\bar{D}}^{\ast }\Sigma$ 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 $D_s^{-}N-\bar{D}\Lambda -\bar{D}\Sigma -{\bar{D}}^{\ast }\Lambda -{\bar{D}}^{\ast }\Sigma$ 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.

Comments: 15 pages, 3 figures and 6 tables