γ-vibrational states in superheavy nuclei

Recent experimental advances have made it possible to study excited structure in superheavy nuclei. The observed states have often been interpreted as quasiparticle excitations. We show that in superheavy nuclei collective vibrations systematically appear as low-energy excitation modes. By using the microscopic Triaxial Projected Shell Model, we make a detailed prediction on γ-vibrational states and their E2 transition probabilities to the ground state band in fermium and nobelium isotopes where active structure research is going on, and in ²⁷⁰Ds, the heaviest isotope where decay data have been obtained for the ground-state and for an isomeric state.