The (6 + ) isomer in 102 Sn revisited: Neutron and proton effective charges close to the double shell closure

In a high-energy fragmentation experiment at GSI an Iπ = (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 1/2 = 367(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 0hω space. The results are discussed in comparison to predicted and empirically determined effective operators.