%0 Journal Article
%A Fraile Prieto, Luis Mario
%A Vedia Fernández, María Victoria
%A Ibáñez García, Paula Beatriz
%A Paziy, Vadym
%A Pérez Liva, Mailyn
%A Picado, E.
%A Vidal, M.
%T Fast-timing study of the l-forbidden 1/2(+) -> 3/2(+) M1 transition in Sn-129
%D 2016
%@ 0556-2813
%U https://hdl.handle.net/20.500.14352/24506
%X The levels in Sn-129 populated from the beta(-) decay of In-129 isomers were investigated at the ISOLDE facility of CERN using the newly commissioned ISOLDE Decay Station (IDS). The lowest 1/2(+) state and the 3/2(+) ground state in 129Sn are expected to have configurations dominated by the neutron s(1/2) (l = 0) and d(3/2) (l = 2) single-particle states, respectively. Consequently, these states should be connected by a somewhat slow l-forbidden M1 transition. Using fast-timing spectroscopy we havemeasured the half-life of the 1/2(+) 315.3-keV state, T-1/2 = 19(10) ps, which corresponds to a moderately fast M1 transition. Shell-model calculations using the CD-Bonn effective interaction, with standard effective charges and g factors, predict a 4-ns half-life for this level. We can reconcile the shell-model calculations to the measured T-1/2 value by the renormalization of the M1 effective operator for neutron holes.
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