Ground states of the Wick-Cutkosky (scalar Yukawa) model using light-front dynamics

We consider the ground state in a model with scalar nucleons and a meson using the formalism of light-front dynamics. Light-front potentials for two-nucleon bound states are calculated using two approaches. First, light-front time-ordered perturbation theory is used to calculate one- and two-meson-exchange potentials. These potentials give results that agree well with the ladder and ladder plus crossed hox Bethe-Salpeter spectra. Secondly, approximations that incorporate nonperturbative physics are used to calculate alternative one-meson-exchange potentials. These nonperturbative potentials give better agreement with the spectra of the full nonperturbative ground-state calculation of our restricted model than the perturbative potentials. For lightly bound states, all of the approaches appear to agree with each other.