Low-spin states of doubly odd 182Au

Decay studies of the long-lived states in Tl186

“…Two levels at 129 and 273 keV known from the β-decay study of 182 Hg(0 + ) are both suggested to have spin 1 or 2 and a negative parity [22]. The feeding of these low-spin levels in the α decay of 186 Tl suggests a low spin for the α-decaying state, despite the fact that this state has a similar half-life to the 10 (−) state (see Sec.…”

“…3). Four of them, 104-, 129-, 144-, and 273-keV transitions, were previously observed and placed in the level scheme in the 182 Hg to 182 Au β-decay study [22]. Based on the α-γ -γ coincidences (see Fig.…”

“…To check the possible α decays of the other long-lived states in 186 Tl, the number of counts in the α-decay spectra gated on the 129-and 273-keV γ -ray transitions were compared to the number of counts in the single-α energy spectrum. To remove the influence of the 5094-keV α particles from the 186 Hg decay, the comparison range was set between 5.4 The 25-keV transition has not been observed; however, it is known from the β-decay studies [22]. The spin parity of the 182 Au ground state is taken from Ref.…”

“…[23] while the spin assignments of the excited states and the placement of the γ -ray transitions are taken from Ref. [22], with an exception of the newly observed 141-keV transition (plotted in red). The spin parity of 186 Tl is taken from Ref.…”

“…Furthermore, the 104-keV transition was not used for gating, because it may also originate from the decay of the (7 + ) state in 182 Au [25]. To account for this feeding, the α-energy spectrum gated on the 129-keV transition was corrected by the total intensity of the 104-keV transition, 32(3)%, from the 182 Hg β-decay studies [22]. From this comparison, the γ -gated-α counts can reproduce 105(7)% of the total number of α counts in the single-α energy spectrum, suggesting that the vast majority of the registered α decays originates from the (2 − ) state (see Sec.…”