It is shown that the striking energy variation in the pd${\to }^3$He η cross section near threshold is probably due to a final state interaction associated with a large (complex) η${\mathrm{-}}^3$He scattering length. The consequences of this hypothesis are studied for the production of the meson in the η${\mathrm{-}}^4$He and η${\mathrm{-}}^7$Be channels.

• Received 30 October 1992

DOI:https://doi.org/10.1103/PhysRevC.47.R938