Relativistic calculations for two- and three-nucleon systems

The relativistic theory for few-nucleon systems developed by Glöckle and Müller is evaluated numerically for a model of scalar particles exchanging scalar mesons to lowest order in the coupling constant. 2-nucleon binding energies and scattering phases and 3-nucleon binding energies are compared with the usual non-relativistic calculation for different choices of the potential. The relativistic treatment gives a weaker binding. The mechanism of this is studied in more detail. We compare our results with the relativistic correction in the 1/c² expansion of Foldy and Krajcik.