Collective excitations of transactinide nuclei in a self-consistent mean field theory

The ATDHFB approach has been applied for a study of properties of collective quadrupole states in several transactinide nuclei: 238U, 240Pu, 242Pu, 246Cm, 248Cm, 250Cf and 252Cf. Calculated energies and B(E2) transition probabilities are in a reasonable agreement with experimental data. Results concerning superdeformed collective states in the 240Pu nucleus are also presented.Comment: 8 pages, 7 figures; presented at 14th Nuclear Physics Workshop (Kazimierz Dolny, Poland, Sept. 2007

Superdeformed oblate superheavy nuclei in the self-consistent approach

The HFB self-consistent method has been applied to study the properties of several neutron deficient superheavy nuclei with Z=120-124, N=160-168. Their distinctive feature is the existence of minima of the total HFB energy for strongly deformed, oblate shapes. The self-consistent results agree quite remarkably with those currently obtained by using microscopic-macroscopic method.Comment: Presented at the Zakopane School on Nuclear Physics "Extremes of the Nuclear Landscape", August 27 - September 2, 2012, Zakopane, Polan

Collective Quadrupole Excitations in Transitional Nuclei

The generalized Bohr Hamiltonian was used to describe the low-lying collective excitations in even-even isotopes of Ru, Pd, Te, Ba and Nd. The Strutinsky collective potential and cranking inertial functions were obtained using the Nilsson potential. The effect of coupling with the pairing vibrations is taken into account approximately when determining the inertial functions. The calculation does not contain any free parameter

Correlation energies by the generator coordinate method: computational aspects for quadrupolar deformations

We investigate truncation schemes to reduce the computational cost of calculating correlations by the generator coordinate method based on mean-field wave functions. As our test nuclei, we take examples for which accurate calculations are available. These include a strongly deformed nucleus, 156Sm, a nucleus with strong pairing, 120Sn, the krypton isotope chain which contains examples of soft deformations, and the lead isotope chain which includes the doubly magic 208Pb. We find that the Gaussian overlap approximation for angular momentum projection is effective and reduces the computational cost by an order of magnitude. Cost savings in the deformation degrees of freedom are harder to realize. A straightforward Gaussian overlap approximation can be applied rather reliably to angular-momentum projected states based on configuration sets having the same sign deformation (prolate or oblate), but matrix elements between prolate and oblate deformations must be treated with more care. We propose a two-dimensional GOA using a triangulation procedure to treat the general case with both kinds of deformation. With the computational gains from these approximations, it should be feasible to carry out a systematic calculation of correlation energies for the nuclear mass table.Comment: 11 pages revtex, 9 eps figure

Low-lying quadrupole collective states of the light and medium Xenon isotopes

Collective low lying levels of light and medium Xenon isotopes are deduced from the Generalized Bohr Hamiltonian (GBH). The microscopic seven functions entering into the GBH are built from a deformed mean field of the Woods-Saxon type. Theoretical spectra are found to be close to the ones of the experimental data taking into account that the calculations are completely microscopic, that is to say, without any fitting of parameters.Comment: 8 pages, 4 figures, 1 tabl

Beyond the relativistic mean-field approximation. III. Collective Hamiltonian in five dimensions

The framework of relativistic energy density functionals is extended to include correlations related to the restoration of broken symmetries and fluctuations of collective variables. A new implementation is developed for the solution of the eigenvalue problem of a five-dimensional collective Hamiltonian for quadrupole vibrational and rotational degrees of freedom, with parameters determined by constrained self-consistent relativistic mean-field calculations for triaxial shapes. The model is tested in a series of illustrative calculations of potential energy surfaces and the resulting collective excitation spectra and transition probabilities of the chain of even-even gadolinium isotopes