Structure of the $K^{\pi }=4^{+}$ bands in ${}^{186,188}\mathrm{Os}$

The (${}^3\mathrm{He}$,$\hspace{0.5em}d$) single-proton stripping reaction has been performed on targets of ${}^{185,187}\mathrm{Re}$ to investigate the structures of the $4_3^{+}$ states in ${}^{186,188}\mathrm{Os}$. The experiment employed 30 MeV ${}^3\mathrm{He}$ beams, and the reaction products were analyzed with a Q3D spectrograph. Absolute cross sections were determined at nine angles between $5^{°}$ and ${50}^{°}$ for states up to approximately 3 MeV in excitation energy. Large ${\frac{5}{2}}^{+}[402]{}_{\pi }+{\frac{3}{2}}^{+}[402]{}_{\pi }$ two-quasiparticle components are deduced for the $4_3^{+}$ levels of both isotopes. Their magnitudes are in agreement with calculations performed using the quasiparticle phonon model, which predicts a coexistence of a large hexadecapole with a smaller, but sizable, $\gamma$-$\gamma$ component in the $4_3^{+}$.

Figure 1

Population of levels in ${}^{186}\mathrm{Os}$ (left) and ${}^{188}\mathrm{Os}$ (right) from (${}^3\mathrm{He}$,$\hspace{0.5em}d$) reactions with a ${40}^{°}$ scattering angle.

Figure 2

Cross section measurements ($\mu$b/sr) compared with DWBA calculations for a single $\ell$ transfer. The dashed and dotted lines represent the optical model parameter sets from Ref. [30] and Ref. [28], respectively. The average spectroscopic strength is reported with a $\pm 30\%$ systematic uncertainty.