New evidence for alpha clustering structure in the ground state band of Po
Ma. von Tresckow (Institut für Kernphysik, Technische Universität Darmstadt, Darmstadt, Germany); M. Rudigier (Institut für Kernphysik, Technische Universität Darmstadt, Darmstadt, Germany); T.M. Shneidman (Joint Institute for Nuclear Research, Dubna, Russia); Th. Kröll (Institut für Kernphysik, Technische Universität Darmstadt, Darmstadt, Germany)
; M. Boromiza (Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH), Bucharest, Romania); et al - Show all 34 authors
Half-lives of the low-lying yrast states of $^{212}$Po have been measured using the delayed coincidence fast-timing method. We report on the first measurement of the half-life, as well as a new measurement of the half-life with improved accuracy compared to previous studies. The extracted lifetime of the and state have been determined to be 100(14) ps and 1.66(28) ns respectively. With these measurements, precise values are now available for the reduced transition strengths B(E2) of all ground state band levels in $^{212}$Po up to the first state, in particular B(E2; ) = 9.4(13) W.u. and B(E2;) = 8.7(15) W.u. Comparison of the new available data with an α-clustering model calculation provides evidence that the inclusion of the α-cluster degree of freedom significantly improves agreement with experimental data compared to earlier shell model calculations.