VARIATIONAL MONTE-CARLO CALCULATIONS OF H-3 AND HE-4 WITH A RELATIVISTIC HAMILTONIAN

The two-nucleon phase shifts and deuteron properties are fitted using relativistic, (m2+p2)1/2, kinetic-energy operators to obtain realistic models of upsilon(ij), the two-nucleon interaction in the frame in which the total momentum P(ij) of the interacting pair is zero. The relativistic Hamiltonian H(R) contains the relativistic kinetic energy, upsilon(ij), and deltaupsilon(ij)(P(ij)) which describes the dependence of the interaction on the total momentum of the pair. The deltaupsilon(ij)(P(ij)) are obtained from the upsilon(ij) using relativistic mechanisms. The ground states of H-3 and He-4 are calculated using the H(R) with the variational Monte Carlo method, and the results are compared with those obtained using the nonrelativistic H(NR). Results of calculations including the three-nucleon interaction are also reported. The relativistic effects reduce the binding energies of H-3 and He-4 by approximately 0.34 and 2.02 MeV, and they do not change the momentum distribution of the nucleons in these nuclei significantly.