A refined version of the Brillouin-Wigner perturbation method is employed to calculate the binding energies of the deuteron and triton with the Reid soft core potential. The method is shown, analytically, to yield an exact treatment of the strong short ranged components of the force. A primary advantage of the procedure is that it yields a variational upper bound on the energy eigenvalue. A formal comparison is made with the $g$ matrix method. It is found that this perturbation procedure is equivalent to seeking an optimum $g$ matrix, which yields the lowest upper bound when two-body correlations are included in the variational wave function. In order to retain the variational property some multiparticle terms are included in the energy series.

NUCLEAR STRUCTURE Brillouin-Wigner perturbation method. Reid soft core potential.

• Received 1 October 1979

DOI:https://doi.org/10.1103/PhysRevC.22.287