The ${\mathrm{\Lambda }}_b\to J\mathrm{/}\psi K^0\mathrm{\Lambda }$ reaction and a hidden-charm pentaquark state with strangeness

We study the ${\mathrm{\Lambda }}_b\to J\mathrm{/}\psi K^0\mathrm{\Lambda }$ reaction considering both the $K^0\mathrm{\Lambda }$ interaction with its coupled channels and the $J\mathrm{/}\psi \mathrm{\Lambda }$ interaction. The latter is described by taking into account the fact that there are predictions for a hidden-charm state with strangeness that couples to $J\mathrm{/}\psi \mathrm{\Lambda }$. By using the coupling of the resonance to $J\mathrm{/}\psi \mathrm{\Lambda }$ from these predictions we show that a neat peak can be observed in the $J\mathrm{/}\psi \mathrm{\Lambda }$ invariant mass distribution, rather stable under changes of unknown magnitudes. In some cases, one finds a dip structure associated to that state, but a signal of the state shows up in the $J\mathrm{/}\psi$ spectrum.