$\eta$-Deuteron Scattering
  Eta-deuteron scattering lengths are calculated. A summation of the multiple scattering series is carried out and the result is checked against more involved calculations. The necessity to go beyond the fixed nucleon approximation is emphasized. It is shown that a quasibound or virtual state in the $\eta$-deuteron system may occur within the range of $\eta$-nucleon scattering lengths suggested by other experiments. 
A.M. Green, J.A. Niskanen (University of Helsinki) and S. Wycech   (Soltan Institute for Nuclear Studies, Warsaw)