Gamma-ray angular distributions in the decays of polarizedLu171,172

Angular distributions of numerous $\gamma$ rays have been measured following the decays of ${}_{}{}^{171,172}{}_{}{}^{}\mathrm{Lu}$ polarized at low temperatures. The magnetic moments of the Lu ground state are deduced to be $\left|\mu \right({}_{}{}^{171}{}_{}{}^{}\mathrm{Lu}\left)\right|=(2.04\mathrm{}\pm 0.10){\mu }_N$ and $\left|\mu \right({}_{}{}^{172}{}_{}{}^{}\mathrm{Lu}\left)\right|=(2.26\mathrm{}\pm 0.10){\mu }_N$. Spin assignments are deduced for several levels in ${}_{}{}^{172}{}_{}{}^{}\mathrm{Yb}$. $\frac{E2\mathrm{}}{M1\mathrm{}}$ and $\frac{M2\mathrm{}}{E1\mathrm{}}$ mixing ratios are deduced for many of the ${}_{}{}^{171}{}_{}{}^{}\mathrm{Yb}$ and ${}_{}{}^{172}{}_{}{}^{}\mathrm{Yb}$ transitions and are compared with expectations based on the intrinsic character of the nuclear levels.