Testing the Interacting-Boson and Interacting Boson-Fermion Approximations by the Study of Radioactive Decay Schemes with the Unisor On-Line Isotope Separator

Configuration Mixing in Pt Nuclei within Interacting Boson Model-2

“…Some nuclei near closed shells appear to have both the vibrational structure expected for a near-spherical shape, and rotational structure, which is typical of deformed nuclei [1]. This phenomenon of shape coexistence involves two configurations of the nucleus which have different numbers of active nucleons.…”

“…In an IBM description, the two configurations have different boson numbers; N v being the same but N π different, or vice versa. The most common situation involves a difference in N π (N v ) of two bosons between the normal configuration and the so-called intruder configuration, corresponding to a pair excitation across a shell or sub-shell gap [1] [2].…”

“…Shape coexistence in atomic nuclei has become a very active field of research during the last decades and clear signals of its existence have been obtained at and near proton or neutron closed shells [1] [2] [3], more in particular in light…”