Shape coexistence studied in 182,184^182,184 Hg via the β decay of 182,184^182,184 Tl

The $beta ^+$ /EC decay $^182,184$ Tl to excited states in the daughter nuclei $^182,184$ Hg has been investigated at the CERN on-line isotope mass separator facility. In both Tl nuclei two β -decaying states were observed. In the case of 184 Tl, narrow-band laser spectroscopy could be used to disentangle the decay of both isomers. In 182 Hg 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 $2_2^+to 2_1^+$ transition in $^182,184$ Hg were measured to be 7.2 (13) and 14.2 (36), respectively, evidencing a strong E0 component