IOP : Shape coexistence studied in ${}^{mathrm{182,184}}$Hg via the β decay of ${}^{mathrm{182,184}}$Tl

The beta(+)/EC decay of Tl-182,Tl-184 to excited states in the daughter nuclei Hg-182,Hg-184 has been investigated at the CERN on-line isotope mass separator facility. In both Tl nuclei two beta-decaying states were observed. In the case of Tl-184, narrow-band laser spectroscopy could be used to disentangle the decay of both isomers. In Hg-182 a precise energy of 335 (1) keV for the 0(2)(+) state was measured together with its feeding from a tentatively proposed 2(3)(+) state at 973 keV. Large conversion coefficients for the 2(2)(+) -> 2(1)(+) transition in Hg-182,Hg-184 were measured to be 7.2 (13) and 14.2 (36), respectively, evidencing a strong E0 component.