How Effective Are Strong Interactions

Effective interactions and transition operators have a long history in nuclear physics. From the early works of Brueckner and Bethe to the present time, microscopic approaches based on realistic nucleon–nucleon interactions, fit to phase shifts, have produced many useful results and insights. Recently, an ab initio approach has been developed that successfully weds a no-core finite basis state treatment, conserving center of mass motion, with an Hermitian effective Hamiltonian derived from realistic two-nucleon and tri-nucleon interactions. We present this approach with a sample of recent results.