Relativistic three-boson bound states in the zero-range limit*

The relativistic Faddeev integral equations are solved to calculate three-boson mass and wave function for ground and excited states. The inputs of relativistic Faddeev integral equations are the fully-off-shell boosted t-matrices, calculated from the boosted interactions by solving the relativistic Lippmann-Schwinger equation. We employ Kamada and Glöcke boosted potentials obtained directly from nonrelativistic short-range separable potentials by solving a quadratic integral equation using an iterative scheme. By adopting Yamaguchi and Gaussian potentials and driving them towards the zero-range limit, we show that relativistic masses and wave functions are model-independent, and the Thomas collapse is avoided, while the nonrelativistic limit keeps the Efimov effect. We compare our results for relativistic masses with Light-Front and Euclidean calculations.