Threshold scattering of the η-meson off light nuclei

The scattering lengths of η-meson collisions with light nuclei 2H, 3H, 3He, and 4He are calculated on the basis of few-body equations in coherent approximation. It is found that the η-nucleus scattering length depends strongly on the number of nucleons and the range parameter. By taking into account the off-shell behavior of the ηN amplitude, the ηα scattering length increases considerably.