CLUSTERING IN YRAST STATES OF NE-20 STUDIED WITH ANTISYMMETRIZED MOLECULAR-DYNAMICS

Structure of the yrast line states of Ne-20 is studied with the Antisymmetrized Molecular Dynamics which is a method free from any model assumption such as the existence of clustering. The construction of the rotating intrinsic states is made by the frictional cooling method under the constraint that the expectation value of the angular momentum Vector takes the given value in its magnitude while its direction is determined variationally. Angular momentum projection is applied to these rotating intrinsic states in order to get good angular momentum states. Two-body spin-orbit force is adapted and nucleon spin orientations expressed by spin coherent states are determined by energy variation, which enables us to describe the dissolution of clusters more satisfactorily. It is found that for both positive and negative parity low spin states, the two-cluster structure of O-16+alpha results as a predominant configuration and that the O-16+alpha clustering becomes weaker as the spin goes up and mixes with the spin-aligned oblate structure when going from 6(+) to 8(+). The yrast states with 10(+), 12(+) and 11(-) are found to have the three-cluster-like structure composed of C-12 cluster and two alpha clusters.