Λb→J/ψK0Λreaction and a hidden-charm pentaquark state with strangeness

Abstract

We study the $\Lambda_{b}\rightarrow J/\psi K^{0}\Lambda$ reaction considering both the $K^{0}\Lambda$ interaction with its coupled channels and the $J/\psi\Lambda$ 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 $J/\psi\Lambda$. By using the coupling of the resonance to $J/\psi\Lambda$ from these predictions we show that a neat peak can be observed in the $J/\psi\Lambda$ 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 $J/\psi$ spectrum.