The shell-model theory of nuclear rotational states

The symplectic model of two of the authors is presented as a simple unified independent-particle-collective model which simultaneously divides the nuclear shell-model space into horizontal layers (independent-particle shells) and vertical slices (invariant collective subspaces). This segmentation of the single-particle space makes it possible to diagonalize a unified model hamiltonian in shell-model space to obtain a description of rare-earth rotational states in remarkably good agreement with experiment. It is shown that the rotational states so obtained span a shell-model space of some 20 major harmonic oscillator shells and challenge the conventional viewpoint that rotational energies are kinetic. (orig.)