Coherent quadrupole-octupole modes and split parity-doublet spectra in odd-Anuclei

Non-yrast spectra of odd-Anuclei in a model of coherent quadrupole-octupole motion

“…the collective energy of the system is obtained in the following analytic form [10] E nk (I, K, πa) = ω 2n + 1 + k 2 + bX(I, K, πa) ,…”

“…Then for a given state belonging to a parity-doublet the core parity is determined as π c = π · π sp . The total core plus particle wave function for a state with an angular momentum I π belonging to a parity-doublet sequence in odd-even nuclei is given by [10] …”

“…In the original application of the model to the yrast octupole spectra it was considered that for a given n the nucleus always takes the lowest quadrupole-octupole vibration states with angular phonon numbers k = 1 or 2 depending on the parity [9,10]. The generalization of the model description by including non-yrast alternatingparity spectra of even-even nuclei showed that a better agreement with the experimental data can be obtained if higher k…”

“…In this work we apply the original concept for the lowest k By using the wave functions (12) one can calculate B(Eλ) transition probabilities (λ = 1, 2, 3) in the yrast and non-yrast quasi-doublet spectra. The relevant formalism was originally developed in [9,10] and further extended to the non-yrast states of even-even nuclei [13]. In this work we apply the formalism developed in [13].…”

“…Recently the model of Coherent Quadrupole-Octupole Motion (CQOM) [9,10] was applied to describe nonyrast collective bands with positive and negative parities in even-even nuclei together with attendant B(E1), B(E2) and B(E3) transition probabilities [13]. It was shown that couples of β-bands and higher-energy (nonyrast) negative-parity bands can be interpreted within the model framework in the same way as the yrast alternating-parity bands.…”