Symmetry-adapted no-core shell model applications for light nuclei with QCD-inspired interactions

We use powerful computational and group-theoretical algorithms to perform ab initio CI (configuration-interaction) calculations in a model space spanned by SU(3) symmetry-adapted many-body configurations with the JISP16 nucleon–nucleon interaction. We demonstrate that the results for the ground states of light nuclei up through A = 16 exhibit a strong dominance of low-spin and high-deformation configurations together with an evident symplectic structure. We also find states among the lowest-lying 0 + eigenstates of 12C and 16O that are clearly dominated by α -clustering correlations. Our findings imply that only a small fraction of the full model space is needed to model nuclear collective dynamics, including deformations and α -particle clustering, even if one uses modern realistic interactions that do not preserve SU(3) symmetry. This, in turn, points to the importance of using a symmetry-adapted CI framework, one based on an LS coupling scheme with the associated spatial configurations organized according to deformation.