Ab initio shell model with a genuine three-nucleon force for the p-shell nuclei -: art. no. 034305

The ab initio no-core shell model (NCSM) is extended to include a realistic three-body interaction in calculations for p-shell nuclei. The NCSM formalism is reviewed and new features needed in calculations with three-body forces are discussed in detail. We present results of first applications to Li-6,Li-7, He-6, Be-7,Be-8,Be-10, B-10,B-11,B-12, N-12, and C-10,C-11,C-12,C-13 using the Argonne V8(') nucleon-nucleon (NN) potential and the Tucson-Melbourne TM'(99) three-nucleon interaction (TNI). In addition to increasing the total binding energy, we observe a substantial sensitivity in the low-lying spectra to the presence of the realistic three-body force and an overall improvement in level ordering and level spacing in comparison to experiment. The greatest sensitivity occurs for states where the spin-orbit interaction strength is known to play a role. In particular, with the TNI we obtain the correct ground-state spin for B-10,B-11,B-12 and N-12, contrary to calculations with NN potentials only.