M1 and E2 Transition Probabilities in Kr Nuclei

In the mass region A=70–90 a richness of nuclear structure effects is caused by energy gaps in the single-particle scheme at different nuclear shapes (oblate, prolate, spherical). These gaps reflect themselves in several minima in the sγ-plane of the potential energy surfaces /1/. Due to the competition of these minima shape coexistence is a general feature in the mass region considered. The nuclei in the central part of that mass region exhibit a very large deformation of e2 ≈ 0.4 already near the ground state /2–4/. Furthermore, very recently the predicted oblate shapes have been proved /5/ in 69,71Se.