Oscillations in the excitation function for complete fusion of at low energies

Inversion doublets of reflection-asymmetric clustering in Si28 and their isoscalar monopole and dipole transitions

“…Many candidates of 24 Mg + α cluster states are observed at more than 10 MeV above the ground state [18][19][20][21][22]. The existence of the 12 C + 16 O molecular resonance above E x 30 MeV is also well known [23][24][25][26][27][28].…”

“…In addition to these highly excited cluster states, the possible clustering of the above-mentioned low-lying mean-field states has attracted much interests and has long been discussed [4,12,[29][30][31][32]. For example, in an antisymmetrized molecular dynamics (AMD) study [4], it was pointed out that the ground-state band and SD band have large overlap with the 24 Mg + α cluster configurations, while the prolate band largely overlaps with the 12 C + 16 O configuration. A similar point was also made using the algebraic cluster model [9,13,33,34].…”

“…The analysis of the wave function shows that the ground state has the duality of an oblate deformed mean field and the clustering of 24 Mg + α and 20 Ne + 8 Be despite the strong influence of the spin-orbit interaction. Because of this duality, by the IS monopole and dipole transitions, the inversion doublets having the 24 Mg + α and 20 Ne + 8 Be configurations are excited as strongly as the single-particle estimates. Hence, it is concluded that the IS monopole and dipole transitions are regarded as a promising probe for these clustering.…”

“…Many candidates of 24 Mg + α cluster states are observed at more than 10 MeV above the ground state [18][19][20][21][22]. The existence of the 12 C + 16 O molecular resonance above E x 30 MeV is also well known [23][24][25][26][27][28]. In addition to these highly excited cluster states, the possible clustering of the above-mentioned low-lying mean-field states has attracted much interests and has long been discussed [4,12,[29][30][31][32].…”

“…The first is the negative-parity cluster bands and the identification of the inversion doublets. The previous AMD study [4] investigated the structure of the positive-parity bands, and found that three positive-parity bands-the ground-state, prolate deformed, and SD bands-have large overlap with the triaxial deformed 24 Mg + α, the 16 O + 12 C, and the axially symmetric 24 Mg + α cluster configurations, respectively. If these bands really have clustering aspects, they must be accompanied by the negative-parity bands to constitute the inversion doublets, because of their reflection-asymmetric intrinsic configurations [35].…”