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. 24.10.Cn, 21.30.Fe, 21.60.Jz, 24.30.Gz Density functional theory is a universal and powerful tool for describing properties of finite nuclei all over the periodic table. In the non-relativistic framework the most successful density functionals are the ones based on density dependent forces, such as the Skyrme [1] or the Gogny [2] functional. Relativistic mean field (RMF) theory was first introduced as a fully fledged quantum field theory by Walecka [3,4]. However, it turned out very soon [5], that for a quantitative description of nuclear surface properties an additional density dependence is necessary. Nowadays RMF theory modified in this form is considered as a covariant form of density functional theory. Over the years it has gained considerable interest, in particular, for the description of nuclei at and far from stability [6,7,8,9,10]. Compared with non-relativistic density functionals covariant density functional theory has certain advantages. They are characterized by a new saturation mechanism obtained by a delicate balance between a strongly attractive scalar field and a strongly repulsive vector field. Moreover, the very large spin-orbit splitting, observed in finite nuclei, is a relativistic effect. Therefore, its treatment in relativistic models arises in a natural way without any additional adjustable parameters. In addition, time-odd mean fields which are important in systems with broken time reversal symmetry are uniquely defined in RMF theory because of the Lorentz covariance of the underlying Lagrangian [11].Pairing properties are essential for a description of nuclei with open shells. They have been included first in the constant gap approximation by occupation numbers of BCS-type [12]. Since this procedure requires the knowledge of the experimental pairing gaps, it cannot be applied in unexplored regions of the nuclear chart, where the binding energies are not known. In addition, it is noted that the BCS approximation breaks down in nuclei far from the valley of stability, where the coupling to the continuum is essential [13]. Therefore the constant gap approximation has been replaced by relativistic Hartree-Bogoliubov (RHB) theory [14] which includes a finite range particle-particle interaction of Gogny form. The details of this theory have been discussed in several review articles [6,7,8] and in the references given there.In any case the adopted functionals are considered universal in the sense that they can be used for nuclei all over the periodic table, where mean field theory is applicable. It is therefore very desirable to find a unique parameteri...

Based on a relativistic mean-field theory with an effective point coupling between the nucleons, three-dimensional angular momentum projection is implemented for the first time to project out states with designed angular momentum from deformed intrinsic states generated by triaxial quadrupole constraints. The same effective parameter set PC-F1 of the effective interaction is used for deriving the mean field and the collective Hamiltonian. Pairing correlations are taken into account by the BCS method using both monopole forces and zero range δ-forces with strength parameters adjusted to experimental even-odd mass differences. The method is applied successfully to the isotopes 24 Mg, 30 Mg, and 32 Mg. PACS numbers: 21.10.-k, 21.10.Re, 21.30.Fe, 21.60.Jz |m = 1 n J m J K≥0

When faced with ambiguous sensory inputs, subjective perception alternates between the different interpretations in a stochastic manner. Such multistable perception phenomena have intrigued scientists and laymen alike for over a century. Despite rigorous investigations, the underlying mechanisms of multistable perception remain elusive. Recent studies using multivariate pattern analysis revealed that activity patterns in posterior visual areas correlate with fluctuating percepts. However, increasing evidence suggests that vision-and perception at large-is an active inferential process involving hierarchical brain systems. We applied searchlight multivariate pattern analysis to functional magnetic resonance imaging signals across the human brain to decode perceptual content during bistable perception and simple unambiguous perception. Although perceptually reflective activity patterns during simple perception localized predominantly to posterior visual regions, bistable perception involved additionally many higher-order frontoparietal and temporal regions. Moreover, compared with simple perception, both top-down and bottom-up influences were dramatically enhanced during bistable perception. We further studied the intermittent presentation of ambiguous images-a condition that is known to elicit perceptual memory. Compared with continuous presentation, intermittent presentation recruited even more higher-order regions and was accompanied by further strengthened top-down influences but relatively weakened bottom-up influences. Taken together, these results strongly support an active top-down inferential process in perception.visual perception | fMRI | MVPA | Granger causality | ambiguous images T he problem of vision entails the constant interpretation of inherently ambiguous local components of a complex scene. In contrast to reduced visual stimuli routinely used in laboratory research such as Gabor patches and isolated faces, natural scenes contain many ambiguities caused by clutter, occlusion, shading, and the inherent complexity of natural objects (1, 2). Similarly, simple daily tasks, such as interpreting the handwriting of another individual, require a level of cognitive capability surmounting that of modern-day computers. The ease with which we are able to rapidly perform such tasks attests to the remarkable capacity of the human visual system, or alternatively, to the vast knowledge and templates stored in the human brain aiding in visual perception (3).Ambiguous images such as the Necker cube and Rubin facevase illusion provide a well-controlled experimental approach to studying the brain's processing when it is faced with ambiguities in sensory inputs. When multiple interpretations of the same sensory inputs are possible, subjective perception alternates between the different interpretations in a stochastic manner (for reviews, see refs. 2 and 4-6). In the case of ambiguous images containing two possible interpretations, this phenomenon is referred to as "bistable perception."Neuroscientific studies of bis...

The E1 strength is systematically analyzed in very neutron-rich Sn nuclei, beyond 132 Sn until 166 Sn, within the Relativistic Quasiparticle Random Phase Approximation. The great neutron excess favors the appearance of a deformed ground state for 142−162 Sn. The evolution of the lowlying strength in deformed nuclei is determined by the interplay of two factors, isospin asymmetry and deformation: while greater neutron excess increases the total low-lying strength, deformation hinders and spreads it. Very neutron rich deformed nuclei may not be as good candidates as stable spherical nuclei like 132 Sn for the experimental study of low-lying E1 strength.