Collective vibrational bands built on two-quasiparticle excitations in Te isotopes - art. no. 024317

The existence and importance of collective vibrational quadrupole bands on top of two-particle excitations in spherical even-even nuclei is investigat ed on the example of Te isotopes. Three types of structures are suggested i n the framework of the quasiparticle-phonon model and are compared to exper imental data systematized from the literature and confirmed by recent exper iments. It is suggested that complex structures of the type [2QPxn phonons] play an important role in the structure of the 8(+) and 10(+) states below 4.5 MeV in the Te isotopes.