Abstract

The potential between heavy hadrons due to pion-exchange can be obtained in the quark model, or from heavy quark and chiral symmetries. The two approaches are shown to be fundamentally equivalent, and general results applicable to both are discussed. Although the existence or otherwise of molecular bound states depends on a poorly-constrained parameter, the pattern of which channels are most susceptible to binding is robust and generic. The predictions of the model are compared to some recent puzzling experimental discoveries for exotic pentaquarks at LHCb.