Clustering and Triaxial Deformations of $^{40}$Ca

Taniguchi, Yasutaka; Kimura, Masaaki; Kanada-En'yo, Yoshiko; Horiuchi, Hisashi

Clustering and Triaxial Deformations of $^{40}$Ca

Authors

Taniguchi, Yasutaka

Kimura, Masaaki

Kanada-En'yo, Yoshiko

Horiuchi, Hisashi

Description

We have studied the positive-parity states of $^{40}$Ca using antisymmetrized molecular dynamics (AMD) and the generator coordinate method (GCM). Imposing two different kinds of constraints on the variational calculation, we have found various kinds of $^{40}{\rm Ca}$ structures such as a deformed-shell structure, as well as $α$-$^{36}$Ar and $^{12}$C-$^{28}$Si cluster structures. After the GCM calculation, we obtained a normal-deformed band and a superdeformed band together with their side bands associated with triaxial deformation. The calculated $B(E2)$ values agreed well with empirical data. It was also found that the normal-deformed and superdeformed bands have a non-negligible $α$-$^{36}$Ar cluster component and $^{12}$C-$^{28}$Si cluster component, respectively. This leads to the presence of an $α$-$^{36}$Ar higher-nodal band occurring above the normal-deformed band.
11pages, 9 figures