The (6 ) Isomer in Sn revisited: Neutron and proton effective charges close to the double shell closure

In a high-energy fragmentation experiment at GSI an I=π(6+) isomer and its γ-decay are identified in $^{102}$Sn, the two-neutron neighbour of the doubly-magic $^{100}$Sn. Its half-life is measured to be T=1/2367(11) ns. The possible existence of further isomers is discussed in the framework of large-scale shell model (LSSM) calculations including up to five particle-hole excitations of the $^{100}$Sn core. From the precise B(E2; 6+→4+) strength and the recently remeasured value for B(E2; 8+→6+) in the two-proton hole neighbour $^{98}$Cd effective E2 polarization charges for protons and neutrons were inferred including LSSM corrections within the full N=4 0ħω space. The results are discussed in comparison to predicted and empirically determined effective operators.