Binding vs. scattering length: $\eta$ in light nuclei
  The possibility of etamesic nuclei remains an open problem in nuclear physics until now. Various calculations give contradictory predictions even for the lightest real nucleus $^3$He. In this paper we present the connection of the binding energy and width to the complex scattering length for 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. 
Jouni A. Niskanen, Hartmut Machner
nucl-th nucl-ex