ηdscattering in the region of theS11resonance

We have studied the reaction $\eta \overrightarrow{d}\eta d$ close to threshold within a nonrelativistic three-body formalism. We considered several $\eta N$ and $\mathrm{NN}$ models, in particular potentials with separable form, fitted to the low-energy $\eta N$ and $\mathrm{NN}$ data to represent the two-body interactions. We found that with realistic two-body interactions a quasibound state does not exist in this system, although there is an enhancement of the cross section by one order of magnitude, in the region near threshold, which is a genuine three-body effect not predicted within the impulse approximation.