Search for excited states in 3H and 3He

The d+N systems are studied in a three-body model, using phenomenological N-N interactions. The scattering matrices are calculated by using the Kohn-Hulthen variational method. Then, they are analytically continued to complex energies and their singularities are localized. We find a virtual state at E = -1.66 MeV in H-3 and a pair of states at E = (-0.42 +/- i0.52) MeV in He-3 relative to the d + N thresholds, respectively. In addition, we discuss some general aspects and problems of virtual states which may be useful also in the study of other systems, like Li-10. [S0556-2813(99)04102-3].