One of the main motivations for the development of ever more powerful exotic beam facilities is the search for phenomena that are either absent or difficult to observe in nuclei close to stability. Among these figure changes in shell structure. For decades the cornerstone of nuclear structure has been the concept of single-particle motion in a well-defined potential leading to shell structure and magic numbers. There is now growing evidence that the magic numbers are not immutable: they appear to depend on the neutron-to-proton asymmetry and the binding energy. This aspect of exotic beam physics will be discussed in this presentation through the example of the appearance of new shell structure in neutron-rich nuclei just above 48Ca. To obtain the results that will be presented, a large number of different experiments and techniques had to be used. In other words, this research is a true experimentalist's dream: for each specific issue the best available technique is required.

ANL Physics Division Colloquium Schedule