BLOCKING EFFECT AND ODD-EVEN DIFFERENCES IN THE MOMENTS OF INERTIA OF RARE-EARTH NUCLEI

A phenomenological analysis of the experimental odd-even differences in the moments of inertia, deltaJ/J, of well-deformed rare-earth nuclei is reviewed, which reveals that there exist large fluctuations in deltaJ/J with the blocked levels in odd-A nuclei. A calculation using the particle-number conserving treatment shows that the odd-even difference in the moments of inertia is a pure quantum mechanical interference effect and the experimental strong fluctuations in deltaJ/J with the blocked level can be reproduced satisfactorily. The calculated value of deltaJ/J depends sensitively on the energetic location and Coriolis response of the blocked level and the underlying physics is discussed. Particularly, deltaJ/J is especially large if the blocked orbital is a high-j intruder orbital near the Fermi surface. In contrast, if the blocked orbital is of normal parity with low j and high OMEGA (e.g., proton [404]7/2, [402]5/2), deltaJ/J almost vanishes.