Cluster aspect of light unstable nuclei

Abstract

We investigated molecular states and cluster gas-like states in light nuclei based on theoretical calculations with antisymmetrized molecular dynamics. The calculated results of 13B suggest that largely deformed states construct rotational bands, K π = 3 / 2 − and K π = 1 / 2 + , starting from 5 MeV and 8 MeV, respectively. The neutron structure of the K π = 3 / 2 − is analogous to the intruder ground state of 12Be. In the predicted K π = 1 / 2 + band, we found largely deformed structure with a proton excited configuration. The band-head 1 / 2 + state is assigned to the 1 / 2 + (4.83 MeV), which was experimentally suggested to be the proton intruder state. Structure of 8He were also investigated. In the results, it was found that the ground state of 8He has both the j- j coupling feature ( p 3 / 2 closure) and the L- S coupling feature ( 4He + 2 n + 2 n ). The results also suggest possible existence of the 0 2 + state with dineutron gas-like structure of 4He + 2 n + 2 n , which has an analogy to the 3 α-cluster structure of the 12C( 0 2 + ) state.