Binding vs. scattering length: η in light nuclei

The possibility of η-mesic nuclei remains an open problem in nuclear physics until now. Various calculations give contradictory predictions even for the lightest real nucleus 3He. In this paper we present the connection of the binding energy and width to the complex scattering length for s-states in heavier nuclei than this in the hope that, with knowledge of the final state interaction this could be useful in searches of possible bound states. It is seen that for a consistent analysis also the effective range should be considered.