Quasiparticle phonon model description of low-energy states in ${}^{152}\mathrm{Pr}$

Delayed $\gamma$-ray and conversion-electron spectroscopy is performed on $A=152$ fission fragments, at the Lohengrin spectrometer of the Institut Laue-Langevin, providing a new decay scheme for ${}^{152}\mathrm{Pr}$. The quasiparticle phonon model, combined with the particle-rotor model, which allows octupole correlations and Coriolis mixing to be taken into account, is applied to analyze its low-energy structure. The main configurations are found to be $(\pi 3/2\left[422\right]\otimes \nu 5/2\left[642\right])1^{+}$ for the isomer and $(\pi 3/2\left[541\right]\otimes \nu 3/2\left[521\right])3^{+}$ for the ground state.

Figure 1

Delayed $\gamma$ rays observed in the Ge detectors in coincidence with $A=152$ ions.

Figure 2

Delayed conversion electrons and photons observed in the Si(Li) detector in delayed coincidence with $A=152$ ions.

Figure 3

Time spectrum of 115.1-keV $\gamma$ rays detected in the Ge detectors, relative to the arrival of an $A=152$ ion.

Figure 4

Partial level scheme of ${}^{152}\mathrm{Pr}$ obtained in this work.

Figure 5

Schematic of the proposed $\beta$ decay of the ground state of ${}^{152}\mathrm{Pr}$ to a $(\nu 3/2\left[521\right]\otimes \nu 3/2\left[532\right])3^{+}$ two-quasiparticle state in ${}^{152}\mathrm{Nd}$.