Decay of the Iπ=8− isomeric state in Nd134 and Pt184 studied by electron and γ spectroscopy

The properties of the $K$-isomer decays in the $^{134}\mathrm{Nd}$ and $^{184}\mathrm{Pt}$ nuclei have been investigated. Measurements were carried out in $e\ensuremath{-}\ensuremath{\gamma}$ and $\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}$ coincidence modes using electron spectrometers coupled to the central European Array for Gamma Levels Evaluations at the Heavy Ion Laboratory of the University of Warsaw. Internal conversion coefficients were obtained for transitions relevant to the decay of the isomeric states, allowing the determination of multipolarities and mixing ratios as well as hindrance factors. Two possible causes of the weakening of the $K$ forbiddenness, namely rotational $K$ mixing (Coriolis interaction) and triaxiality, are briefly discussed using schematic theoretical models.