  We consider spin-chain-star systems characterized by N-wise many-body
interactions between the spins in each chain and the central one. We show that
such systems can be exactly mapped into standard spin-star systems through
unitary transformations. Such an approach allows the solution of the dynamic
problem of an XX spin-chain-star model and transparently shows the emergence of
quantum correlations in the system, based on the idea of entanglement between
chains.
