Phase-Shift Analysis ofO16(α, α)O

α-cluster structure ofO18

“…We conclude that unlike for the N = Z, 16 O and 20 Ne nuclei, the α-strength is split about evenly between two or more states for each spin-parity and it is not possible to define inversion doublet rotational bands in the same sense as for 16 O and 20 Ne. The Cluster-Nucleon Configuration Interaction Model (CNCIM) calculations presented in section V indicate that splitting of the α-strength for the positive parity band is a result of (1s0d) 4 (8, 0) [4] and (0p) 2 (1s0d) 2 (6, 0) [4] configuration mixing. For the negative parity states and the very broad positive parity states the (1p0f) shell (not included in the CNCIM) probably plays an important role.…”

“…This splitting of α-strength is due to the strong mixture of (1s0d) 4 (8, 0) [4] and (0p) 2 (1s0d) 2 (6, 0) [4] configurations. In the excitation energy region between 8 and 13 MeV, six 0 + states restricted to p-sd-shell configuration are predicted.…”

“…These bands are called inversion doublets and have been conclusively identified in 16 O and 20 Ne (see Fig. 1) [1][2][3][4][5][6][7][8]. There have been numerous attempts to find the members of the inversion doublet rotational bands in 18 O that correspond to an 14 C(g.s.…”

“…Here the nucleon configurations are listed together with the corresponding (λ, µ) quantum numbers of the SU(3) symmetry. The permutational symmetry is fixed as [f ] = [4].…”

“…All members of these bands that have excitation energies above the α-decay threshold, posses α-reduced widths close to the single particle limit, indicating their extreme α-cluster character. Extensive experimental and theoretical studies [1][2][3][4][5][6][7][8] have suggested an interpretation of these bands as well developed α+core structures.…”