P.-G. Reinhard

Electric dipole polarizability and the neutron skin

The recent high-resolution measurement of the electric dipole (E1) polarizability {alpha}{sub D} in {sup 208}Pb [A. Tamii et al. Phys. Rev. Lett. 107 062502 (2011)] provides a unique constraint on the neutron-skin thickness of this nucleus. The neutron-skin thickness r{sub skin} of {sup 208}Pb is a quantity of critical importance for our understanding of a variety of nuclear and astrophysical phenomena. To assess the model dependence of the correlation between {alpha}{sub D} and r{sub skin}, we carry out systematic calculations for {sup 208}Pb, {sup 132}Sn, and {sup 48}Ca based on the nuclear density functional theory using both nonrelativistic and relativistic energy density functionals. Our analysis indicates that whereas individual models exhibit a linear dependence between {alpha}{sub D} and r{sub skin}, this correlation is not universal when one combines predictions from a host of different models. By averaging over these model predictions, we provide estimates with associated systematic errors for r{sub skin} and {alpha}{sub D} for the nuclei under consideration. We conclude that precise measurements of r{sub skin} in both {sup 48}Ca and {sup 208}Pb - combined with the recent measurement of {alpha}{sub D} - should significantly constrain the isovector sector of the nuclear energy density functional.

Boost-invariant mean field approximation and the nuclear Landau-Zener effect

We investigate the relation between time-dependent Hartree-Fock (TDHF) states and the adiabatic eigenstates by constructing a boost-invariant single-particle Hamiltonian. The method is numerically realized within a full three-dimensional TDHF which includes all the terms of the Skyrme energy functional and without any symmetry restrictions. The study of free translational motion of a nucleus demonstrates the validity of the concept of boost-invariant and adiabatic TDHF states. The interpretation is further corroborated by the test case of fusion of 16 O + 16 O. As a first application, we present a study of the nuclear Landau-Zener effect on a collision of 4 He + 16 O.

Appearance of the single gyroid network phase in “nuclear pasta” matter

Nuclear matter under the conditions of a supernova explosion unfolds into a rich variety of spatially structured phases, called nuclear pasta. We investigate the role of periodic networklike structures with negatively curved interfaces in nuclear pasta structures, by static and dynamic Hartree-Fock simulations in periodic lattices. As the most prominent result, we identify for the first time the single gyroid network structure of cubic chiral I4123 symmetry, a well-known configuration in nanostructured soft-matter systems, both as a dynamical state and as a cooled static solution. Single gyroid structures form spontaneously in the course of the dynamical simulations. Most of them are isomeric states. The very small energy differences from the ground state indicate its relevance for structures in nuclear pasta.

Application of an extended random-phase approximation to giant resonances in light-, medium-, and heavy-mass nuclei

We present results of the time blocking approximation (TBA) for giant resonances in light-, medium-, and heavy-mass nuclei. The TBA is an extension of the widely used random-phase approximation (RPA) adding complex configurations by coupling to phonon excitations. A new method for handling the single-particle continuum is developed and applied in the present calculations. We investigate in detail the dependence of the numerical results on the size of the single-particle space and the number of phonons as well as on nuclear matter properties. Our approach is self-consistent, based on an energy-density functional of Skyrme type where we used seven different parameter sets. The numerical results are compared with experimental data.

Nuclear charge and neutron radii and nuclear matter: Trend analysis in Skyrme density-functional-theory approach

Radii of charge and neutron distributions are fundamental nuclear properties. They depend on both nuclear interaction parameters related to the equation of state of infinite nuclear matter and on quantal shell effects, which are strongly impacted by the presence of nuclear surface. In this work, by studying the dependence of charge and neutron radii, and neutron skin, on nuclear matter parameters, we assess different mechanisms that drive nuclear sizes. We apply nuclear density functional theory using a family of Skyrme functionals obtained by means of different optimization protocols targeting specific nuclear properties. By performing the Monte-Carlo sampling of reasonable functionals around the optimal parametrization, we study correlations between nuclear matter paramaters and observables characterizing charge and neutron distributions. We demonstrate the existence of the strong converse relation between the nuclear charge radii and the saturation density of symmetric nuclear matter and also between the neutron skins and the slope of the symmetry energy. For functionals optimized to experimental binding energies only, proton and neutron radii are weakly correlated due to canceling trends from different nuclear matter parameters. We show that by requiring that the nuclear functional reproduces the empirical saturation point of symmetric nuclear matter practically fixes the charge (or proton) radii, and vice versa. The neutron skin uncertainty primarily depends on the slope of the symmetry energy. Consequently, imposing a constraint on both

Nuclear Energy Density Optimization: UNEDF2

rho_0

Exotic cluster structures in the mean-field theory

and

Nuclear Pasta at Finite Temperature with the Time-Dependent Hartree-Fock Approach

L

Minimal surfaces in nuclear pasta with the Time-Dependent Hartree-Fock approach

practically determines the nuclear size, modulo small variations due to shell effects.

Excitation spectra of exotic nuclei in a self-consistent phonon-coupling model.

M. Kortelainen1,2,3,4, J. McDonnell3,4,5, W. Nazarewicz3,4,6, E. Olsen3, P.-G. Reinhard7, J. Sarich8, N. Schunck5,3,4, S. M. Wild8, D. Davesne9, J. Erler10, A. Pastore11 1Department of Physics, University of Jyvaskyla, P.O. Box 35 (YFL), FI-40014 Jyvaskyla, Finland 2Helsinki Institute of Physics, P.O. Box 64, FI-00014 University of Helsinki, Finland 3Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, USA 4Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA 5Physics Division, Lawrence Livermore National Laboratory, Livermore, CA 94551, USA 6Institute of Theoretical Physics, Warsaw University, ul. Hoza 69, PL-00681, Warsaw, Poland 7Institut fur Theoretische Physik, Universitat Erlangen, D-91054 Erlangen, Germany 8Mathematics and Computer Science Division, Argonne National Laboratory, Argonne, IL 60439, USA 9Institut de Physique Nucleaire de Lyon, CNRS-IN2P3, UMR 5822, Universite Lyon 1, F-69622 Villeurbanne, France 10Division of Biophysics of Macromolecules, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, D-69120 Heidelberg, Germany 11Institut d’Astronomie et d’Astrophysique, Universite Libre de Bruxelles CP226, 1050 Brussels, Belgium