High-spin studies of¹⁶⁴Lu using EUROBALL

Summary

A new region of superdeformed shapes with a pronounced triaxiality coexisting with normal deformation exists for nuclei withN ~ 94 andZ ~ 71. Calculations with the Ultimate Cranker have revealed that triaxial SD minima with γ ~ ±20° are expected for all symmetry groups (π, α). In an odd-odd nucleus, the possibility exists to exploit the various combinations of proton and neutron orbitals which are expected to sample the triaxial minima differently. A search for such structures was performed as one of the first Euroball experiments using the reaction¹³⁹La(²⁹Si,4n) with thin self-supporting targets at a beam energy of 145 MeV, provided by the Legnaro XTU tandem accelerator. The preliminary analysis has provided a major extension of the known (normal deformed) level scheme in¹⁶⁴Lu, in addition to ~7 new, presumably triaxial, SD bands in¹⁶⁴Lu. These bands have dynamical moments of inertia similar to those found in^163,165Lu. The new data are compared to expectations from calculations with the code “Ultimate Cranker”.