Nuclear structure in the region of 100Sn at N≃Z

With the recent development of efficient γ-arrays with highly selective ancillary detectors, studies of shell structure and residual interaction in exotic nuclei like 100Sn have become feasible. The shell structure at N=Z=50 (100Sn) shows a remarkable similarity to N=Z=28 (56Ni), albeit recent experiments on the 100Sn neighbors 102,104Sn and 98Cd indicate substantial and puzzling deviations in the E2 and E3 polarizability of the magic core 1–3. New experimental results and their shell model interpretation are discussed.