Novel methods for determining effective interactions for the nuclear shell model

The contractor renormalization (CORE) method is applied in combination with modern effective-theory techniques to the nuclear many-body problem. A one-dimensional—yet “realistic”—nucleon-nucleon potential is introduced to test these novel ideas. It is found that the magnitude of “model-space” (CORE) corrections diminishes considerably when an effective potential that eliminates the hard-momentum components of the potential is first introduced. As a result, accurate predictions for the ground-state energy of the three-body system are made with relatively little computational effort when both techniques are used in a complementary fashion.