Figure 1

Level scheme for ${}^{157}\mathrm{Dy}$ deduced in this work. Energies are given in kiloelectronvolts; tentative transitions and levels are indicated by dotted lines; and tentative spin, parity, and level energies are given within parentheses.Reuse & Permissions

Figure 2

High-energy part of a triple gated, summed coincidence spectrum for the yrast band (band 5) in ${}^{157}\mathrm{Dy}$ obtained from the Euroball IV experiment.Reuse & Permissions

Figure 3

Triple-gated, summed coincidence spectra for (a) band 2 and (b) band 1 in ${}^{157}\mathrm{Dy}$ derived from the Gammasphere experiment.Reuse & Permissions

Figure 4

Triple-gated, summed coincidence spectra for (a) band 4 and (b) bands 7 and 8 in ${}^{157}\mathrm{Dy}$ obtained from the Gammasphere experiment.Reuse & Permissions

Figure 5

The level schemes deduced for ${}^{158}\mathrm{Dy}$ and ${}^{159}\mathrm{Dy}$. Energy values are in kiloelectronvolts, tentative transitions are indicated by dotted lines and tentative spin, and parity and level energies are given within parentheses.Reuse & Permissions

Figure 6

Double-gated, summed coincidence spectra of (a) band 1 ($\pi ,\alpha =$) (+,0), (b) band 2 (−,0), (c) band 3 (−,1) bands in ${}^{158}\mathrm{Dy}$, and (d) band 1 (+,+½) band in ${}^{159}\mathrm{Dy}$. The 760-, 958-, 757-, 838-, and 932-keV side-feeding transitions in ${}^{158}\mathrm{Dy}$ are marked with asterisks.Reuse & Permissions

Figure 7

Experimental alignment (i) versus rotational frequency ($\hslash \omega$) for bands in ${}^{157}\mathrm{Dy}$. The band crossings are labeled at the appropriate rotational frequencies [37, 36]. The AB, BC, and AD labels refer to the first, second, and third $i_{13/2}$ neutron crossings and the $A_p{B}_p$ label to the first $h_{11/2}$ proton crossing. Harris parameters of $\omega {}_0=32$ MeV${}^{-1}\hslash {}^2$ and $\omega {}_1=34$ MeV${}^{-3}\hslash {}^4$ were used. These provide a constant alignment above $\hslash \omega =$ 0.2 MeV for the three-quasiparticle configuration $(B_p\mathrm{AB})$ in ${}^{157}\mathrm{Ho}$ [38], included as a common reference trajectory (dotted) in each of the panels.Reuse & Permissions

Figure 8

Experimental alignment (i) versus rotational frequency ($\hslash \omega$) for bands in ${}^{158}\mathrm{Dy}$. The band crossings are labeled at the appropriate rotational frequencies [37, 36]. The AB and BC labels refer to the first and second $i_{13/2}$ neutron crossings and the $A_p{B}_p$ label to the first $h_{11/2}$ proton crossing. Harris parameters of $\omega {}_0=32$ MeV${}^{-1}\hslash {}^2$ and $\omega {}_1=34$ MeV${}^{-3}\hslash {}^4$ were used. These provide a constant alignment above $\hslash \omega =$ 0.2 MeV for the three-quasiparticle configuration $(B_p\mathrm{AB})$ in ${}^{157}\mathrm{Ho}$ [38], included as a reference trajectory (dotted) for comparison.Reuse & Permissions

Figure 9

Experimental alignments i versus rotational frequency $\hslash \omega$ for (a) odd-N ${}^{155-159}\mathrm{Dy}$ isotopes, and (b) the yrast bands of even-$N,{}^{154-160}\mathrm{Dy}$. The band crossings are labeled at the appropriate rotational frequencies [37, 36]. Harris parameters of $\omega {}_0=32$ MeV${}^{-1}\hslash {}^2$ and $\omega {}_1=34$ MeV${}^{-3}\hslash {}^4$ were used. Information for the other Dy isotopes is taken from Ref. 16(${}^{154}\mathrm{Dy}$), Ref. 17, 18(${}^{155}\mathrm{Dy}$), Ref. 11 (${}^{156}\mathrm{Dy}$), and Ref. 40(${}^{160}\mathrm{Dy}$).Reuse & Permissions

Figure 10

Experimental alignments i versus rotational frequency $\hslash \omega$ for (a) (+,+1/2) bands in N = 91 isotones, (b) (+,0) bands in N = 92 isotones, and (c) (+,+1/2) bands in N = 93 isotones. The band crossings are labeled at the appropriate rotational frequencies [37, 36]. Harris parameters of $\omega {}_0=32$ MeV${}^{-1}\hspace{1em}\hslash {}^2$ and $\omega {}_1=34$ MeV${}^{-3}\hslash {}^4$ were used. References (apart from the Dy isotopes presented in this work) are as follows: (a) for N = 91 isotones Ref. 46 ${}^{155}\mathrm{Gd}$, Ref. 4 ${}^{159}\mathrm{Er}$, Ref. 47 ${}^{161}\mathrm{Yb}$, Ref. 48 ${}^{163}\mathrm{Hf}$, and Ref. 49 ${}^{165}\mathrm{W}$; (b) for $N=92$ isotones Ref. 50 ${}^{154}\mathrm{Sm}$, Ref. 51 ${}^{156}\mathrm{Gd}$, Ref. 6 ${}^{160}\mathrm{Er}$, Ref. 52 ${}^{162}\mathrm{Yb}$, and Ref. 10, 53 ${}^{164}\mathrm{Hf}$; and (c) $N=93$ isotones Ref. 8 ${}^{161}\mathrm{Er}$, Ref. 54 ${}^{163}\mathrm{Yb}$, Ref. 53 ${}^{165}\mathrm{Hf}$, Ref. 55 ${}^{167}\mathrm{W}$.Reuse & Permissions

Figure 11

The observed bands of ${}^{157}\mathrm{Dy}$ (upper panel) and the calculated configurations drawn relative to a rigid rotor reference, $E_{\mathrm{rot}}=A\times I(I+1)$. The experimental bands are labeled by their parity, signature, and band number. The calculated configurations are labeled by their parity, signature, and the number of occupied $N=5,h_{11/2}$ proton and $N=6,i_{13/2}$ neutron orbitals, e.g., $\pi 5^6\nu 6^2=[6,2]$ (with the number of $h_{11/2}$ neutron holes in parentheses if applicable). Closed symbols are used for signature $\alpha =+1/2$ and open symbols for $\alpha =-1/2$. The $I_{max}$ states (see text) are shown by large open circles or large open squares, depending on if the lowest energy minimum for this spin value is calculated at $\gamma ={60}^{°}$ or at a triaxial shape. The present configurations build the yrast line up to $I\approx 60$, but for higher spin values configurations with protons in the higher shells, $h_{9/2}$ and $i_{13/2}$, come lower in energy as indicated by the asterisk symbols. (Note that the subtracted rigid rotor reference values $[A(\mathrm{expt})=0.0075$ MeV and A(theory) = 0.007 MeV] have been chosen such that the slope of the (+,1/2) yrast trajectories at $I=35\hslash$ are similar in theory and experiment. The large differences in curvature at low spin values can be traced to the fact that the calculations do not include pairing correlations.)Reuse & Permissions