Lifetime measurements in ${}^{112}\mathrm{Sb}$

Lifetimes of some high-spin states in the negative parity magnetic dipole band in ${}^{112}\mathrm{Sb}$ were determined using the Doppler-shift attenuation method. The deduced $M1$ transition rates show a small decrease with increasing spin. This decrease is reasonably accounted for within the framework of the tilted axis cranking (TAC) model. There also appears to be a considerable contribution from collective rotation. This is the first indication of such behavior in the $A\approx 110$ mass region, determined through lifetime measurements. The TAC calculations based on a $\pi g{{}_{9/2}}^{-1}\otimes \nu h_{11/2}$ configuration reproduce the magnetic dipole band.

Figure 1

Partial level scheme of ${}^{112}\mathrm{Sb}$ showing the band under study [12].

Figure 2

Experimental data and associated line-shape fits for 391.6 and 353.6 keV transitions. The spectra were obtained from a combination of clean gates on the stopped transitions in the cascade. The spectra are labeled by the angles at which the detectors were situated.

Figure 3

$B(M1)$ values versus angular momentum band 1 in Fig. 1. The solid line represents the results from the TAC calculations.

Figure 4

Angular momentum as a function of level energy. The solid line represents the results from the TAC calculations.