0+ states in the large boson number limit of the Interacting Boson Approximation model
/ Authors
/ Abstract
Studies of the Interacting Boson Approximation (IBA) model for large boson numbers have been triggered by the discovery of shape/phase transitions between different limiting symmetries of the model. These transitions become sharper in the large boson number limit, revealing previously unnoticed regularities, which also survive to a large extent for finite boson numbers, corresponding to valence nucleon pairs in collective nuclei. It is shown that energies of 0n+ states grow linearly with their ordinal number n in all three limiting symmetries of IBA [U(5), SU(3), and O(6)]. Furthermore, it is proved that the narrow transition region separating the symmetry triangle of the IBA into a spherical and a deformed region is described quite well by the degeneracies E(02+) = E(61+, E(03+) = E(101+), E(04+) = E(141+, while the energy ratio E(61+)/E(02+ turns out to be a simple, empirical, easy‐to‐measure effective order parameter, distinguishing between first‐ and second‐order transitions. The energies of 0n+ state...
Journal: arXiv: Nuclear Theory
DOI: 10.1063/1.3039862