New Constraint of Clustering for AMD and Its Application to the Study of the 2 -12C Structure of 20Ne

A new constraint of clustering for the AMD calculation is proposed. This newconstraint gives us large improvement in studying the cluster structure by AMDwhich sometimes meets difficulty in giving rise to some specific clusterconfigurations. The usefulness of this new constraint is verified by applyingit to the the study of the third $K^\pi = 0^+$ band of $^{20}$Ne which has beendiscussed to have $2\alpha$-$^{12}$C structure. This band has not been easyeven to construct by AMD. We see that the AMD+GCM calculation by the use of thenew constraint gives rise to the third $K^\pi = 0^+$ band which contains the$2\alpha$-$^{12}$C structure as an important component.Comment: 13 pages, 4 figure