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${}^{\pi }=\left({6}^{+}\right)$ 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${}_{1/2}=367\left(11\right)$ 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; ${6}^{+}\to {4}^{+}$) strength and the recently remeasured value for B(E2; ${8}^{+}\to {6}^{+}$) 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 $0ħ\omega $ space. The results are discussed in comparison to predicted and empirically determined effective operators.