Figure 1

A part of the $\alpha$-decay spectrum collected in the silicon detectors in Run I (HRS). The $\alpha$ peaks are denoted with their energies in keV and the isotope to which they belong.Reuse & Permissions

Figure 2

(a) Time distribution for the 6560-keV $\alpha$ decay of ${}^{179}$Tl${}^g$ from ISOLDE data, determined using as reference the times of two consecutive proton pulses indicated as 1${}^{\mathrm{st}}$ PP and 2${}^{\mathrm{nd}}$ PP in the figure, respectively. The “decay” part of the time distribution was fitted with an exponential function, shown by the red line, resulting in the half-life value of 263(17) ms; (b) time distribution between the recoil implantations and subsequent ${\alpha }_1$(6561-keV) decays of ${}^{179}$Tl${}^g$ from the SHIP experiment by using the triple correlation events ER-${\alpha }_1$(6561)-${\alpha }_2$(6433). The fit, shown with a red solid line, was performed with a combination of an exponential decay and a constant background, resulting in a half-life value of 267(13) ms; (c) time distribution between the two correlated $\alpha$ decays from the ER-${\alpha }_1$(6561)-${\alpha }_2$(6433) analysis of the SHIP data. The same fit as for panel (b) was performed, giving the half-life value of 207(7) ms for ${}^{175}$Au${}^g$.Reuse & Permissions

Figure 3

(Right-hand side) The decay scheme of ${}^{179}$Tl${}^g$ deduced in the present study. For comparison and to support the discussion, the decay scheme of ${}^{179}$Tl${}^m$ from [7] is shown on the left-hand side of the figure. The $\alpha$-decay energies $E_{\alpha }$, the half-life values $T_{1/2}$, the $\alpha$-decay branching ratios $b_{\alpha }$, and the reduced $\alpha$-decay widths ${\delta }_{\alpha }^2$ are indicated for each isotope. The quoted $\alpha$-decay energies for ${}^{179}$Tl${}^g$ and ${}^{175}$Au${}^g$ are weighted averages from the SHIP and ISOLDE experiments. The $\alpha$-decay branching ratios of ${}^{179}$Tl${}^g$ and ${}^{175}$Au${}^g$ are from the ISOLDE data. The half-life value of ${}^{175}$Au${}^g$ is from the SHIP experiment. The tentative estimates of the excitation energies of the isomeric states (the $\Delta$ values) are given in the text. The indicated statistical uncertainties of $\alpha$-decay energies from the present work are from the Gaussian fits of the respective peaks. A typical systematical uncertainty of $\sim 5$ keV should be added due to the calibration procedures used at SHIP and ISOLDE.Reuse & Permissions

Figure 4

(a) Part of the ${\alpha }_1$-energy spectrum from the reaction ${}^{40}$Ca+${}^{144}$Sm$\to {}^{184}$Pb${}^{*}$ registered within 2000 ms after the ER implantation in the PSSD. $\alpha$-decay energies are given in keV. (b) The ${\alpha }_1$-${\alpha }_2$ correlation plot for the ${\alpha }_1$ decay from the panel (a), measured within the time interval of $\Delta$$T$(${\alpha }_1$-${\alpha }_2$)$\le$1200 ms.Reuse & Permissions

Figure 5

Experimental excitation energies of the 11/2${}^{-}$ states in the lightest odd-$A$ Re, Ir, Au, and Tl isotopes, relative to the 1/2${}^{+}$ states, where known. Data are from [19, 29, 30, 31]. Open red circles mark the expected position of the 11/2${}^{-}$ states in ${}^{179}$Tl${}^m$ and ${}^{175}$Au${}^m$, obtained from the linear interpolation, and in ${}^{171}$Ir${}^m$ and ${}^{167}$Re${}^g$ from the linear extrapolation of the energies of known 11/2${}^{-}$ states in the respective isotopic chains. The dashed red line connects the states in the $\alpha$-decay chain ${}^{179}$Tl${}^m$$\to$${}^{175}$Au${}^m$$\to$${}^{171}$Ir${}^m$$\to$${}^{167}$Re${}^g$. The 9/2${}^{-}$ intruder states in ${}^{181,183}$Tl are also shown. See the text for further details.Reuse & Permissions