Seminarium Fizyki Jądra Atomowego

The study of collective behavior of deformed nuclei is a classical problem in nuclear physics. Mean-field descriptions in the intrinsic frame are perfectly suited for such studies, as they take advantage of the spontaneous breaking of rotational symmetry. The price to pay is the loss of angular momentum as a good quantum number. On the other hand, in the nuclear shell model defined in the laboratory frame angular momentum is conserved but the physical insight associated with the existence of the intrinsic state is lost. In this talk, I will discuss recent shell model results for nuclei above 78Ni core, where collectivity and triaxiality may occur. The results will be analyzed by means of collective and symmetry models and compared to predictions of the self-consistent, symmetry conserving beyond mean-field calculations. Recent experimental results supporting theoretical predictions will be also shown. Further, shell model and experimental results pointing to analogous phenomena emerging above 132Sn core will be discussed.If time allows, I will also show new shell model developments towards the description of low energy radiative strength, which is a basic ingredient of neutron capture cross section calculations.