Bound 0⁺ Excited States of Three-Body Systems with Short-Range Two-Body Interactions

The Faddeev equations are solved to investigate the bound states of three-body systems with short-range two-body interactions. Different bound 0⁺ excited states are obtained depending on the mass ratios of particles, when there is no bound state for two-body sub-systems. On the one hand, a number of bound 0⁺ excited states appear in the system with two heavy particles and a light particle. On the other hand, a weakly bound 0⁺ excited state is obtained in the system with two light particles and a heavy particle, which has not been reported in previous works as far as we know.