Nature of low-energy excited 0+ states and associated bands in actinide nuclei

Determine the microscopic structure and provide an appropriate theoretical description of the low-energy excited 0+ states and their corresponding Kπ=0+ bands observed in actinide and related nuclei, including whether they arise from shape coexistence, pairing vibrations, or multi-octupole-phonon configurations.

Background

The paper discusses low-energy excited 0+ states and associated rotational bands as recurring features of nuclear structure. In actinide nuclei near (N,Z)≈(134,88), enhanced octupole collectivity has motivated the interpretation of some low-lying 0+ states as possible two-octupole-phonon excitations, while alternative explanations invoke shape coexistence or pairing vibrations.

Although the study applies a density-functional-theory-mapped interacting boson model containing quadrupole and octupole bosons, its stated motivation is that the general interpretation of these low-energy 0+ states and corresponding Kπ=0+ bands remains unresolved. The present calculations provide evidence for substantial multi-octupole-boson components, but the broader microscopic interpretation is identified as an open problem rather than conclusively settled.