Detailed spectroscopy and $\gamma \text{−}\gamma$ angular correlation measurements of ${}_{122}\mathrm{Xe}$

Excited states of ${}_{122}\mathrm{Xe}$ populated via ${\beta }^{+}$ and electron capture (EC) decay of ${}_{122}\mathrm{Cs}$ have been studied with $\gamma$-ray spectroscopy using the $8\pi$ spectrometer at the TRIUMF Isotope Separator and Accelerator facility. Two sets of data were collected to optimize the signal-to-background ratio for decays of the ground ($t_{1/2}=21.2$ s) and isomeric ($t_{1/2}=3.7$ min) states of ${}_{122}\mathrm{Cs}$. The data collected have enabled the observation of 520 transitions and 191 levels, including eight new excited $0^{+}$ states in ${}_{122}\mathrm{Xe}$. The $\gamma \text{−}\gamma$ angular correlations have been analyzed that permitted the assignment or restriction of the spins for 66 levels. The $E2/M1$ multipolarity mixing ratios for 38 $\gamma$-ray transitions were also extracted from these analyses. Low-spin members of the $0_2^{+}, 0_3^{+}, 0_4^{+}$, and $K^{\pi }=4^{+}$ bands are assigned, as well as suggested $K^{\pi }=2_2^{+}$ and $K^{\pi }=2_3^{+}$ bandheads. Combined with previous results for high-spin states, rotational bands built on a newly assigned $K^{\pi }=3_1^{-}$ state and its $4_1^{-}$ signature partner, the $5_2^{-}$ and its $6_2^{-}$ signature partner, are suggested. The results for the positive-parity bands are compared with a model using a general Bohr Hamiltonian derived from a mean-field theory based on the UNEDF0 energy-density functional that displays good overall agreement.