相关论文: E2 and M1 strengths in heavy deformed nuclei
Inter-band B(E2) transition strengths between different normal parity bands in 163Dy and 165Er are described using the pseudo-SU(3) model. The Hamiltonian includes Nilsson single-particle energies, quadrupole-quadrupole and pairing…
Rotational bands of positive and negative parity are frequently found experimentally in heavy deformed even-even nuclei along with their corresponding $E2$ intra-band and $E1$ inter-band transitions. In $SU(3)$ symmetry-based models,…
Spectrum and electric dipole transition rates and relative intensities in $^{152-154}$Sm, $^{156-160}$Gd, $^{160-162}$Dy are studied in the framework of the interacting boson model with s,p,d,f bosons. It is found that E1 transition data…
Pseudo-SU(3) shell-model results are reported for M1 excitation strengths in 157-Gd, 163-Dy and 169-Tm in the energy range between 2 and 4 MeV. Non-zero pseudo-spin couplings between the configurations play a very important role in…
The low-energy spectra and B(E2) electromagnetic transition strengths of 159Eu, 159Tb and 159Dy are described using the pseudo SU(3) model. Normal parity bands are built as linear combinations of SU(3) states, which are the direct product…
Magnetic dipole strength functions have been deduced from averages of a large number of $M1$ transition strengths calculated within the shell model for the nuclides $^{90}$Zr, $^{94}$Mo, $^{95}$Mo, and $^{96}$Mo. An enhancement of $M1$…
Within the unified model of Bohr and Mottelson we derive the following linear energy weighted sum rule for low energy orbital 1$^+$ excitations in even-even deformed nuclei $$S_{\rm LE}^{\rm lew} (M_1^{\rm orb}) \cong (6/5) \epsilon (B(E2;…
Analytical formulas for the excitation energies as well as for the electric quadrupole reduced transition probabilities in the ground, beta and gamma bands were derived within the coherent state model for the near vibrational and well…
The pseudo-SU(3) model is used to describe the low-energy spectra as well as $E2$ and $M1$ transition strengths in $^{158}$Gd. The Hamiltonian includes spherical single-particle energies, the quadrupole-quadrupole and proton and neutron…
We present a review of the pseudo-SU(3) shell model and its application to heavy deformed nuclei. The model have been applied to describe the low energy spectra, B(E2) and B(M1) values. A systematic study of each part of the interaction…
Electric quadrupole strength functions have been deduced from averages of a large number of $E2$ transition strengths calculated within the shell model for the nuclides $^{94}$Mo and $^{95}$Mo. These strength functions are at variance with…
Normal parity bands are studied in 157Gd, 163Dy and 169Tm using the pseudo SU(3) shell model. Energies and B(E2) transition strengths of states belonging to six low-lying rotational bands with the same parity in each nuclei are presented.…
The 62Sm, 64Gd, 64Dy, 70Y b, 72Hf and 74W nuclei are classified as deformed nuclei. Low-lying bands are one of the most fundamental excitation modes in the energy spectra of deformed nuclei. In this paper a theoretical analysis of the…
We calculate reduced B(E2) and B(M1) electromagnetic transition strengths within and between K-bands in support of a recently proposed model for the structure of heavy nuclei. Previously, only spectra and a rough indication of the largest…
Microscopic studies in heavy nuclei are very scarce due to large valence spaces involved. This computational problem can be avoided by means of the use of symmetry based models. Ground-state, gamma and beta-bands, and their B(E2) transition…
Using group theoretical and numerical methods we have calculated the exact energy spectrum of the two-dimensional Hubbard model on square lattices with four electrons for a wide range of the interaction strength. All known symmetries, i.e.\…
Low-lying electric-dipole ($E1$) strength of a neutron-rich nucleus contains information on neutron-skin thickness, deformation, and shell evolution. We discuss the possibility of making use of total reaction cross sections on $^{40}$Ca,…
We study low-lying multipole strength in neutron-halo nuclei. The strength depends only on a few low-energy constants: the neutron separation energy, the asymptotic normalization coefficient of the bound state wave function, and the…
A collective vector-boson model with broken SU(3) symmetry, in which the ground state band and the lowest $\gamma$ band belong to the same irreducible representation but are non-degenerate, is applied to several deformed even-even nuclei.…
We derive analytic expressions for the energies and $B(E2)$-transition probabilities in the states of the ground and $\gamma$ bands of heavy deformed nuclei within a collective Vector-Boson Model with SU(3) dynamical symmetry. On this basis…