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Abstract: Systematic investigation of the accuracy of the description of the energies of deformed one-quasiparticle states has been performed in covariant density functional theory in actinide and rare-earth mass regions. The sources of the discrepancies between theory and experiment are analyzed. Although some improvements in the description of ground state configurations and one-quasiparticle spectra can be achieved by better parametrization of the relativistic mean field Lagrangian, the analysis suggests that spectroscopic quality of their description can be achieved only in theoretical framework which takes into account particle–vibration coupling. [Copyright &y& Elsevier]

Modern applications of Covariant Density Functional Theory (CDFT) are discussed. First we show a systematic investigation of fission barriers in actinide nuclei within constraint relativistic mean field theory allowing for triaxial deformations. In the second part we discuss a microscopic theory of quantum phase transitions (QPT) based on the relativistic generator coordinate method. [ABSTRACT FROM AUTHOR]

Abstract: The impact of pairing correlations on the fission barriers is investigated in Relativistic Hartree–Bogoliubov (RHB) theory and Relativistic Mean Field (RMF)+BCS calculations. It is found that the pairing gap changes considerably with deformation and RMF+BCS calculations with constant gap do not provide an adequate description of the barriers. RHB calculations show that there is a substantial difference in the predicted barrier heights between zero-range and finite range pairing forces even in the case when the pairing strengths of these two forces are adjusted to the same value of the pairing gap at the ground state. For zero range forces the barrier heights depend on the renormalization procedure. [Copyright &y& Elsevier]

Abstract: We present a review of recent applications of self-consistent relativistic mean-field models to exotic nuclear structure. Based on concepts of non-renormalizable effective relativistic field theories and density functional theory, these models provide a rich theoretical framework for studies of nuclei along the valley of -stability, exotic nuclei with extreme ground-state isospin values and close to the particle drip lines. A quantitative microscopic description of ground states and properties of excited states in nuclei far from stability necessitates a unified description of mean-field and pairing correlations. The relativistic Hartree–Bogoliubov (RHB) model has been employed in studies of structure phenomena that include: the description of the neutron drip line in light nuclei and the microscopic mechanism for the formation of neutron halos; the reduction of the effective spin–orbit interaction and the resulting modification of surface properties in drip line nuclei; the suppression of shell effects and the onset of deformation and shape coexistence in neutron-rich nuclei; nuclei at the proton drip-line and ground-state proton emitters in the region of deformed rare-earth nuclei; shape coexistence phenomena in neutron-deficient nuclei. The cranked RHB framework has been used for the description of rotational excitations: superdeformed and highly deformed rotational bands in the mass region, rotational bands built on superdeformed minima in the and the mass regions, and on normal deformed minima in the rare-earth region, smooth termination of rotational bands, rotational and quasiparticle properties of the heaviest actinide nuclei. The relativistic random phase approximation (RRPA) has been employed in studies of nuclear compression modes, nuclear matter asymmetry energy, multipole giant resonances and low-lying collective states in spherical nuclei, the evolution of the low-lying isovector dipole response in nuclei with a large neutron excess, pygmy resonances, isoscalar dipole and toroidal dipole resonances. The relativistic quasiparticle RPA, formulated in the canonical single-nucleon basis of the RHB, has been applied in the description of the low-energy multipole response of unstable weakly bound nuclei. The self-consistent relativistic mean-field framework has been extended to include density-dependent meson–nucleon vertex functions. Compared with standard relativistic effective interactions with non-linear meson-exchange terms, the density-dependent meson–nucleon couplings provide an improved description of asymmetric nuclear matter, neutron matter and nuclei far from stability. Effective density-dependent interactions have also been used in relativistic (Q)RPA calculations of giant resonances, and in a microscopic analysis of the nuclear matter compressibility and symmetry energy. [Copyright &y& Elsevier]

Parametric correlations are studied in several classes of covariant density functional theories (CDFTs) using a statistical analysis in a large parameter hyperspace. In the present manuscript, we investigate such correlations for two specific types of models, namely, for models with density dependent meson exchange and for point coupling models. Combined with the results obtained previously in Ref. [1] for a non-linear meson exchange model, these results indicate that parametric correlations exist in all major classes of CDFTs when the functionals are fitted to the ground state properties of finite nuclei and to nuclear matter properties. In particular, for the density dependence in the isoscalar channel only one parameter is really independent. Accounting for these facts potentially allows one to reduce the number of free parameters considerably. [ABSTRACT FROM AUTHOR]

Abstract: Covariant density functional theory based on the relativistic mean field (RMF) Lagrangian with the parameter set NL3 has been used in the last ten years with great success. Now we propose a modification of this parameter set, which improves the description of the ground state properties of many nuclei and simultaneously provides an excellent description of excited states with collective character in spherical as well as in deformed nuclei. [Copyright &y& Elsevier]