NO-CORE SHELL MODEL FOR NUCLEAR STRUCTURE AND REACTIONS

The no-core shell model (NCSM), in which all A nucleons are treated as active, is an ab initio approach for calculating the properties of nuclei microscopically. We first present the basic NCSM formalism, which allows us to exactly determine the effective Hamiltonian as well as any general operator in a model space of arbitrary size for performing shell-model calculations. Good results for binding energies and spectra have been obtained for nuclei up to mass A = 14 using the best available two-nucleon (NN) and theoretical three-nucleon forces (3NF's). We next present three new applications and extensions of the NCSM approach: I) the use of the NCSM in the three-nucleon (3N) cluster approximation as a method for testing the reliability of different 3NF's, and the application of the NCSM to 2) other general operators and 3) inclusive electromagnetic responses.