Spurious poles in hadronic three-particle problems

The particle-dimer picture is a useful tool to simplify the three-particle problem by including information about the two-particle system. However, in higher orders the dimer propagator can exhibit spurious poles. We present a non-perturbative approach to deal with this problem and compare to fully perturbative schemes. The proposed approach might prove to be more convenient for the generalization in a finite volume. The method is tested with a Yamaguchi model potential.