Looking for a hidden-charm pentaquark state with strangeness $S=-1$ from ${\Xi }_b^{-}$ decay into $J/\psi K^{-}\Lambda$

Abstract

Assuming that the recently observed hidden-charm pentaquark state, $P_c(4450)$, is of molecular nature as predicted in the unitary approach, we propose to study the decay of ${\Xi }_b^{-}\to J/\psi K^{-}\Lambda$ to search for the strangeness counterpart of the $P_c(4450)$. There are three ingredients in the decay mechanism: the weak decay mechanism, the hadronization mechanism, and the finite state interactions in the meson-baryon system of strangeness $S=-2$ and isospin $I=1/2$ and of the $J/\psi \Lambda$. All these have been tested extensively. As a result, we provide a genuine prediction of the differential cross section where a strangeness hidden-charm pentaquark state, the counterpart of the $P_c(4450)$, can be clearly seen. The decay rate is estimated to be of similar magnitude as the ${\Lambda }_b^0\to J/\psi K^{-}p$ observed by the LHCb collaboration.

Comments: 7 pages, 5 figures; typos corrected