Inelastic neutron scattering studies of 132,134Xe: Elucidating structure in a transitional region and possible interferences for 0vββ searches

Highly enriched (> 99.9%) 132 Xe and 134 Xe gases were converted to solid 132 XeF2 and 134 XeF2 and were used as scattering samples for inelastic neutron scattering measurements at the University of Kentucky Accelerator Laboratory (UKAL). Lifetimes of levels up to 3.5 MeV in excitation energy in these xenon isotopes were measured using the Doppler-shift attenuation method, allowing the determination of reduced transition probabilities. Gamma rays corresponding to new transitions and levels have been observed. In particular, tentative new excited 0 + states and associated decays have been examined in an effort to elucidate the structure of these nuclei in a transitional region, and comparisons have been drawn with models which seek to describe such nuclei, e.g., the E(5) critical-point symmetry of the IBM. Newly identified potential interferences for neutrinoless double-beta decay searches involving 136 Xe are also discussed.