Energy levels in the nucleus /sup 156/Dy through the /sup 159 /Tb(p,4n gamma )/sup 156/Dy reaction

Abstract

Using the /sup 159/Tb(p,4n gamma )/sup 156/Dy reaction at /b E//sub p/=27 to 51 MeV and standard on-line gamma -ray spectroscopy methods, the energies and decay properties of members of various rotational bands in the nucleus /sup 156/Dy have been investigated, i.e. the ground-state band up to 14/sub g//sup +/, the beta -vibrational band up to 14/sub beta //sup +/, the gamma -vibrational band up to 11 /sub gamma //sup +/, and two other bands, one with odd-spin levels up to 11, the other with even-spin levels up to 10. The results are compared with various calculations in the framework of the collective model, and no satisfactory fit is obtained; possible improvements of the model to remove these discrepancies are suggested.Anglai