Resumo

MCCUTCHAN, E.A.. An old approach for new investigations in the IBA symmetry triangle. Rev. mex. fis. [online]. 2006, vol.52, suppl.4, pp.62-66. ISSN 0035-001X.

Motivated by the success of the X(5) critical point model in describing the properties of certain rare-earth nuclei, IBA-1 calculations are performed for rare-earth isotopic chains. Contours of basic observables are discussed and used to extract parameter values. The properties of all low-lying positive parity excitations are well described for a wide range of nuclei and the resulting parameters are mapped into the IBA symmetry triangle. The simple, two parameter IBA-1 calculations are also extended to the Pt isotopic chain. Both energies and electromagnetic transition strengths are are found to be well described over the entire isotopic chain suggesting these nuclei can be described more simply without the need for introducing an intruder configuration.

Palavras-chave : Interacting boson model; collective levels; B(E2) values.