Band crossing in a shears band of ${}^{108}\mathrm{Cd}$

The level lifetimes have been measured for a shears band of ${}^{108}\mathrm{Cd}$ that exhibits band crossing. The observed level energies and $B(M1)$ rates have been successfully described by a semiclassical geometric model based on shear mechanism. In this geometric model, the band crossing in the shears band has been described as the reopening of the angle between the blades of a shear.

Figure 1

Experimental and theoretical line shapes for the 316-, 522-, 362-, and 482-keV $\gamma$ rays of ${}^{108}\mathrm{Cd}$ at ${79}^{°}$ and ${139}^{°}$ with respect to the beam direction on the top and bottom panels, respectively. The contamination peaks are shown by dotted lines and theoretical line shapes are shown by solid lines.

Figure 2

The effective interaction $V_2$ between the blades of the shear, ${\mathit{j}}_{\parallel }$ and ${\mathit{j}}_{\perp }$, as a function of the shears angle before the band crossing (a) and after (b). The solid line is the fit to the experimental data for (a) $V_2=1.65$ MeV and (b) $V_2=2.65$ MeV.

Figure 3

Experimentally evaluated $B(M1)$ rates as a function of angular momentum in ${}^{108}\mathrm{Cd}$ and ${}^{110}\mathrm{Cd}$ [1]. The value for the $I^{\pi }={22}^{-}$ level in ${}^{108}\mathrm{Cd}$ has been taken from Ref. [2]. The solid and the dashed lines denote the theoretical values from the semiclassical model for ${}^{108}\mathrm{Cd}$ and ${}^{110}\mathrm{Cd}$, respectively.