Analysis of the triaxial, strongly deformed bands in odd-odd nucleus Lu-164 with the tops-on-top model

The top-on-top model with angular-momentum-dependent moments of inertia is extended to the tops-on-top model for an odd-odd nucleus, where one proton and one neutron in each single-j orbital are coupled to the triaxial rotor. For a pure rotor case, an explicit algebraic formula for the triaxial, strongly deformed (TSD) band levels is given, and its stability problem is discussed. Both positive and negative parity TSD bands are well reproduced by taking account of attenuation factors in the Coriolis interaction and the proton-neutron interaction in the recoil term. Difference in quantum numbers between the yrast and yrare TSD bands is confirmed by direct estimation of spin alignments. The electromagnetic transition rates of B(M1) are much reduced because of the different sign of g-factors in comparison with the odd-A case, while B(E2) are in the same order.