X-ray– fast-timing lifetime measurement of the state in
Résumé
Low-lying states in were investigated using the fast-timing technique with and high-purity germanium detectors. The excited states in this nucleus were populated via two consecutive electron capture decays from . The parent isotope was produced in the fusion-evaporation reaction at the FN-Tandem facility at the Institute for Nuclear Physics, University of Cologne. The previously known value for the lifetime of the state in was confirmed using the generalized centroid difference (GCD) method. The lifetime of the state was determined from decay in the first application of the GCD method for x-ray– coincidences. A Monte Carlo based approach was applied to address the indirect population of the state by the decay of . The experimental results were examined in the context of the transition of single-particle excitations to collective behavior in the neutron-deficient Po isotopes. The obtained value suggests that for the states in even-even Po isotopes the transition from a noncollective regime at to a collective regime occurs at .