Pentaquarks and strange tetraquark mesons

We consider the interplay of the pentaquark states and strange tetraquark states in the decay ${\mathrm{\Lambda }}_b^0\to K^{-}J\mathrm{/}\psi p$. Possible existence of ($cs\bar{c}\bar{u}$)-states is taken up and their manifestation in the $K^{-}J\mathrm{/}\psi$-channel is discussed. It is emphasised that these exotic mesons can imitate broad bumps in the in the $pJ\mathrm{/}\psi$-channel.