Gamma-ray transitions between excited states in¹⁶⁸Er

Abstract

The intensities and reduced probabilities of the E1, E2, M1 and M2 transitions between excited states in 168Er are calculated within the quasiparticle-phonon nuclear model. The intensities and reduced probabilities are in reasonably good overall agreement with experimental ones. It is shown that the contribution of the two-phonon configuration to the wavefunction of excited states with energy below 2 MeV is small. The wavefunction of the first Knu pi =41+ state contains the largest double-gamma vibrational term equal to 30%. The dominance of the decay from the first excited 01+ state to the gamma vibrational state over that to the ground state band is in agreement with the experimental data. The specific features of the calculated B(E1), B(E2) and B(M1) values and the relative intensities of the gamma-ray transitions are discussed.

Dipole strength distribution and specific properties of excitations in the second minimum in actinide nuclei

“…Other phonons are calculated with the ph and pp isoscalar and isovector multipole interactions. The relevant RPA equations are given in [12,13,14,15].…”

“…Vibrational states and gamma-ray transition rates in welldeformed doubly even nuclei have been calculated within the quasiparticle-phonon nuclear model (QPNM) [12,13,14,15,16]. The QPNM is used for a microscopic description of the low-spin, small-amplitude vibrational states in spherical nuclei not far from closed shells and well-deformed nuclei.…”

Systematics of low-lying dipole strengths in odd and even Dy and Gd isotopes

“…Besides these more or less macroscopic collective descriptions, microscopic calculations for E1 excitations in deformed nuclei were reported by Soloviev and co-workers [64,65]. These authors calculated within the framework of the quasiparticle-phonon-nuclear-model (QPNM) excitation energies, wave functions, and E1 transition strengths for the deformed rare earth nuclei ' Gd, '6 ' Dy, and ' Fr, explicitly.…”

Microscopic studies of two-phonon giant resonances

“…This is true for the case of spherical nuclei where only the coupling of two GDR phonons to more complex, 3p3h, configurations allows one to describe the DGDR width as discussed above. But the typical matrix element of this coupling in deformed nuclei does not exceed the value of 200 keV [120] while in spherical nuclei it is an order of magnitude larger. It means that due to the coupling, the strength of each GDR RPA-phonon will fragment within the energy interval of 100-200 keV in deformed nuclei.…”