An attractive ϕ-4 theory in light-front coordinates

We study an attractive ϕ-4 interaction using Tamm-Dancoff truncation with light-front coordinates in 3+1 dimensions. The truncated theory requires a coupling constant renormalization, we compute its β function non-perturbatively, show that the model is asymptotically free, and find the corresponding Callan-Symanzik equations. The model supports bound states, we find the wave function of the ground state of the two-particle sector. We also give a bound for the N-particle ground state energy within a mean field approximation, including the corresponding result for the case of 2+1 dimensions where the model does not require renormalization.