Electromagnetic properties of low-lying levels of Xe 129

Unperturbed and perturbed angular correlation and conversion electron measurements have been performed to obtain spectroscopic information on the low-lying levels of $^{129}\mathrm{Xe}$ fed by the decay of $^{129}\mathrm{Cs}$. We established ${I}^{\ensuremath{\pi}}(318\mathrm{keV})={\frac{3}{2}}^{+}$, ${I}^{\ensuremath{\pi}}(411\mathrm{keV})={\frac{1}{2}}^{+}$, ${I}^{\ensuremath{\pi}}(589\mathrm{keV})={\frac{3}{2}}^{+}$, $\ensuremath{\delta}(39.6\mathrm{keV})=\ensuremath{-}(2.6\ifmmode\pm\else\textpm\fi{}0.5)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$, $\ensuremath{\delta}(177\mathrm{keV})=0.44\ifmmode\pm\else\textpm\fi{}013$, $\ensuremath{\delta}(372\mathrm{keV})=+0.97\ifmmode\pm\else\textpm\fi{}0.09$, $\ensuremath{\mu}(39.6\mathrm{keV})=+(0.88\ifmmode\pm\else\textpm\fi{}0.26){\ensuremath{\mu}}_{N}$. $B(M1)$ and $B(E2)$ values are derived from above data and earlier lifetime determinations. A weak-coupling calculation is presented to explain experimental data.