Investigating $Z_{cs}(3985)$ and $Z_{cs}(4000)$ exotic states in ${\Lambda }_b\to Z_{cs}^{-}p$ decays

Abstract

We study the $Z_{cs}(3985)$ and $Z_{cs}(4000)$ exotic states in the decays of ${\Lambda }_b$ baryons through a molecular scenario. In the final state interaction, the ${\Lambda }_b\to {\Lambda }_c^{+}{D}_s^{(\ast )-}$ decays are followed by the ${\Lambda }_c^{+}{D}_s^{(\ast )-}$ to $Z_{cs}^{-}p$ rescatterings via exchange of a $D^{(\ast )}$ meson. We predict a branching fraction of $(3.1_{-2.6}^{+1.4})\times 10^{-4}$ for ${\Lambda }_b\to Z_{cs}^{-}p$, which can be measured in the ${\Lambda }_b\to J/\psi K^{(\ast )-}p$ decay. This study proposes a new approach to test the molecular model, and guides future experimental searches for the $Z_{cs}(3985)$ and $Z_{cs}(4000)$.

Comments: 13 pages, 3 figures