Lifetimes in $^{211}$At and their implications for the nuclear structure above $^{208}$Pb

International audienceLifetimes of excited states in At211 were measured using the electronic γ-γ fast timing technique. The nucleus of interest was populated in a Pb208(Li6,3n)At211 fusion-evaporation reaction at the FN Tandem accelerator of the Institute for Nuclear Physics, University of Cologne. The lifetimes of the 17/21− and 23/21− states were determined, together with an upper limit for the 13/21− state. The experimental results are compared to two shell-model calculations, one using a semiempirical interaction for three particles in a single j=9/2 shell and the other using the modified Kuo-Herling interaction in a multi-j model space