$\alpha$-cluster excited states in ${}^{32}$S

Abstract

$\alpha$-cluster excited states in ${}^{32}$S are investigated with an extended ${}^{28}$Si+$\alpha$ cluster model, in which the ${}^{28}$Si core deformation and rotation, and the $\alpha$-cluster breaking are incorporated. In the GCM calculation with the extended ${}^{28}$Si+$\alpha$ cluster model, the $\alpha$-cluster excited states are obtained near the ${}^{28}$Si+$\alpha$ threshold energy. The ${}^{28}$Si core deformation and rotation effects, and also the $\alpha$-clusters breaking in the ${}^{28}$Si+$\alpha$ system are discussed. It is found that the rotation of the oblately deformed ${}^{28}$Si core gives a significant effect to the $\alpha$-cluster excited states whereas the $\alpha$-cluster breaking gives only a minor effect.