The resonances $X(4140)$, $X(4160)$, and $P_{cs}(4459)$ in the decay of ${\mathrm{\Lambda }}_b\to J\mathrm{/}\psi \mathrm{\Lambda }\varphi$

We study the decay of ${\mathrm{\Lambda }}_b\to J\mathrm{/}\psi \mathrm{\Lambda }\varphi$ by taking into account the intermediate resonances $X(4140)$, $X(4160)$, and $P_{cs}(4459)$. In addition to the peak of the $X(4140)$, we also find a bump structure around 4160 MeV followed by a cusp structure around $D_s^{\ast }{\bar{D}}_s^{\ast }$ threshold in the $J\mathrm{/}\psi \varphi$ invariant mass distribution of the $\Lambda_b\to J/\psi\Lambda\phi$process,whichcanbeassociatedtothe$D^_s\bar{D}^_s$molecularstate$X(4160)$. We also show that this reaction can also be used to confirm the existence of the hidden-charm pentaquark $P_{cs}(4459)$ with strangeness. We predict an enhancement structure close to the threshold in the $D_s^{\ast }{\bar{D}}_s^{\ast }$ invariant mass distribution of the $\Lambda_b\to D^_s\bar{D}^_s\Lambda$process,whichisthereflectionofthe$X(4160)$ and should not be misidentified with a new resonance. We strongly suggest experimentalists to further measure these processes, which can be useful to clarify the nature of $X(4140)$ and $X(4160)$ resonances, and to confirm the existence of the $P_{cs}(4459)$.