Approximate ways to treat the nucleon-nucleon tensor force in the four-nucleon bound state

Several approximation methods are tested in the four-nucleon bound-state problem as a means to understand how the two-nucleon tensor force propagates through the underlying (2)+(2) and (3)+1 subsystem amplitudes to yield a final four-nucleon binding energy. The aim is to show how to include as much of the nucleon-nucleon tensor force as possible in the dominant S-state component of the four-nucleon wave function for the purpose of optimizing the starting point in the iterative solution of the full problem