Saturation of B(E2)-strength near mid-shell? Lifetimes of ^{174,176,178,180}Hf

Deformed nuclei in the rare earth region should show a saturation of the B(E2;0⁺₁ → 2⁺₁)-transition strength near mid-shell. Recent measurements of lifetimes of W-isotopes show discrepancies to literature values and seem to maximize the B(E2)-strength off mid-shell. An analog investigation is done on Hf-isotopes. Several lifetimes of excited states of the even-even isotopes ^{174,176,178,180}Hf have been measured with fast electronic scintillation timing (FEST) using the same experimental setup to minimize systematic deviations among the values. Excited States were populated via Coulomb excitation (¹⁸⁰Hf) and via β⁺-decay following fusion-evaporation reactions (^174,176,178Hf) at the 9 MV tandem accelerator of the IFIN-HH near Bucharest. Obtained lifetimes of the Hf-isotopes will be presented.