Nonadditivity in nuclear moments of inertia and interference between blocking effects

The experimentally observed obvious nonadditivity in the nuclear moment of inertia and angular momentum alignment of multiquasiparticle rotational bands, both in normally deformed and superdeformed nuclei, presents a serious challenge to the traditional BCS treatment for nuclear pairing. It is shown that the systematically observed nonadditivity mainly comes from the destructive interference between blocking effects, and can be satisfactorily accounted for by the particle-number conserving method, in which the blocking effects are treated consistently and exactly.