E0 transitions in the light tellurium isotopes: evidence for intruder states

Investigation of shape coexistence in 118–128Te isotopes

“…The reduced electric monopole and quadrupole transition probabilities are considered as the observables which as well as the quadrupole moment ratios within the low-lying state bands prepare more information about the nuclear structure. The most general single-boson transition operator of angular momentum has the form [5,7] ( ) in above equation as [5,7] ( )…”

“…On the other hand, the E2 transition operator must be a Hermitian tensor of rank two and consequently, number of bosons must be conserved. With these constraints, there are two operators possible in the lowest order, therefore the electric quadrupole transition operator employed in this study is defined as [7],…”

“…IBM-2 predictions for B(E0) and B(E2) transition probabilities are presented for some transitions between excited bounds which their experimental counterparts are available. Experimental values are taken form Refs [5,7,[65][66][67][68][69][70][71][72]…”

Study of shape coexistence in the 180−190Hg isotopes by SO(6) representation of eigenstates

“…transfer reactions in particular, very near to closed shells (the In and Sb nuclei at Z=50 but also in other mass regions, e.g. the Tl and Bi nuclei at Z=82) some low-lying extra states, so-called intruder states, have been observed with a conspicuous energy dependence on the number of free valence neutrons, hinting for 2p-2h excitations as their origin [49][50][51][52][53][54][55][56][57][58][59][60][61]. If these excitations are proton excitations combined with the neutron degree of freedom appearing on both sides of the Z=50 closed shell, such as condition which are available for Te isotopes, it is a natural step to suggest that low-lying extra 0 + excitations will also show up in the even-even nuclei in between.…”

“…Very important information about the shape-coexisting states in this region has been extracted in α-decay studies of fusion products, especially when detecting γ rays or electrons in coincidence with α particles . 3 There are two naturally complementary ways in order to describe the phenomenon of nuclear shape coexistence [45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62]. The first one is model that starts from a nuclear shell-model approach, protons and neutrons are expected to gradually fill the various shells at Z, N = 2, 8, 20, 28, ... giving rise to a number of double-closed shell nuclei that are the reference points determining shells.…”