Microscopic structure of low-lying $0^{+}$ states in deformed nuclei

We adopt the microscopic quasiparticle-phonon model to carry out a systematic study of the low-lying excited $0^{+}$ states observed in large abundance in some deformed nuclei. Through the investigation of the energy levels, the corresponding wave functions, the E0 and E2 transition probabilities, and, especially, the two-nucleon transfer spectroscopic factors, we gain a deep insight into the nature of these states and are able to single the properties shared by all nuclei from the ones induced by the peculiar shell structure of each system.

Figure 1

(Color online) QPM versus experimental data in ${}^{168}\mathrm{Er}$. These include the energies of the $0^{+}$ states (top panel), the energy distribution of the $(p,t)$ spectroscopic factors (middle), and their running sum (bottom). The experimental data are taken from Refs. 3, 4.

Figure 2

(Color online) Energy levels in some actinides. The experimental data are taken from Ref. 2.

Figure 3

(Color online) Strength distribution of the two lowest octupole two-phonon components among different QPM $0^{+}$ states in ${}^{230}\mathrm{Th}$.

Figure 4

(Color online) Experimental versus QPM energy distributions of $(p,t)$ spectroscopic factors in the actinides. The experimental data are taken from Ref. 2.

Figure 5

(Color online) Experimental versus computed running sums of $(p,t)$ spectroscopic factors. The experimental data are taken from Ref. 2.

Figure 6

(Color online) The contribution to the running sum of the $(p,t)$ transfer amplitudes coming from the forward ψ (dash line) and backward ϕ (dot-dashed line) RPA amplitudes for two states.