Rotational properties of the superheavy nucleus 256Rf and its neighboring even-even nuclei in a particle-number-conserving cranked shell model

The ground state band was recently observed in the superheavy nucleus ²⁵⁶Rf. We study the rotational properties of ²⁵⁶Rf and its neighboring even-even nuclei by using a cranked shell model (CSM) with the pairing correlations treated by a particle-number conserving (PNC) method in which the blocking effects are taken into account exactly. The kinematic and dynamic moments of inertia of the ground state bands in these nuclei are well reproduced by the theory. The spin of the lowest observed state in ²⁵⁶Rf is determined by comparing the experimental kinematic moments of inertia with the PNC-CSM calculations and agrees with previous spin assignment. The effects of the high order deformation ɛ₆ on the angular momentum alignments and dynamic moments of inertia in these nuclei are discussed.