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The Coriolis matrix elements responsible for mixing of the 1 + K = 1 and 1 + K = 0 states are calculated in the framework of the Quasiparticle Phonon Model for several Gd and Dy isotopes. In many considered cases these matrix elements are equal to several tens of keV and are comparable with energy distances between the mixed levels. The results obtained indicates that Gd isotopes could be more suitable for finding deviations from Alaga rules in M1 transitions from 1 + state to the states of the ground band. [ABSTRACT FROM AUTHOR]

In this paper, the ratio of the mass coefficients for the γ-vibrational and rotational motion for the well deformed axially symmetric nuclei is calculated. Calculations are performed based on the Cranking model approach. The results obtained show that the microscopic model based on the Woods-Saxon nuclear mean field potential and the pairing forces with a constant strength coefficient qualitatively explain the existing experimental data on the ratio of the mass coefficients. The important role of the blocking effect in the calculation of the mass coefficients is demonstrated. [ABSTRACT FROM AUTHOR]

The Generator Coordinate Method (GCM) is used to construct the effective nuclear density operator suitable for calculations of E0 transitional densities with collective eigenfunctions of the phenomenological Bohr Hamiltonian. For example, the 0+ gs $ \rightarrow$ 0+ 2 transitional density is calculated for the shape-phase transitional nucleus 150Nd using the eigenfunctions of the approximate X(5) solution of the Bohr Hamiltonian. [ABSTRACT FROM AUTHOR]

A neutron number dependence of the E1 0+ 1 → 1- 1 reduced transition probability in spherical even-even nuclei is analysed within the Q-phonon approach in the fermionic space to describe the structure of collective states. Microscopic calculations of the E1 0+ 1 → 1- 1 transition matrix elements are carried out for the Xe isotopes based on the RPA for the ground-state wave function. A satisfactory description of the experimental data is obtained. [ABSTRACT FROM AUTHOR]

Vibrational states built on the K[sup π] = 9[sup -] isomer and on the ground state (K[sup π] = 1[sup +]) in [sup 180]Ta are calculated within the quasiparticle-phonon nuclear model using the [sup 178]Hf nucleus as a core. A procedure for calculating the rates of K-allowed γ-ray transitions from vibrational states built on the isomer to those built on the ground state is presented. The probabilities of two-step processes consisting of a dipole excitation of the isomer and successive E1 and E2 transitions from them to vibrational states built on the ground state of the [sup 180]Ta nucleus are calculated. Two-step transitions from the isomer to vibrational states below 2.7 MeV and to the vibrational states built on the ground state appear to be very weak. There are many E1 transitions from the vibrational states built on the isomer to the vibrational states built on the ground state. They are weak and cannot be responsible for the strong deexcitation of [sup 180m]Ta in the relevant (γ,γ) reaction. A decisive role is played by collective E2 transitions from dipole excitations in several excitation energy intervals ranging between 2.7 and 4.0 MeV. These highly intense K-allowed two-step γ-ray transitions can be responsible for the strong deexcitation of the [sup 180m]Ta state in the (γ,γ') reactions. [ABSTRACT FROM AUTHOR]

M1 and E1 transition rates from the ground to excited states and between excited states in 238U are calculated within the quasiparticle-phonon nuclear model with the wave functions consisting of one- and two-phonon terms. We show that there are relatively large M1 transitions between 2+ states in the low-energy region. The fragmentation of the one-phonon states strongly affects M1 and E1 strength distributions. The correlation takes place between E1 and E3 transition strengths. We show that there are fast E1 and M1 transitions between large components of the wave functions differing by an octupole or quadrupole phonon. [ABSTRACT FROM AUTHOR]