Orateur
Description
The mean-field, or Energy Density Functional (EDF), methods allow for the study of energies and
shapes of all nuclei, but the lightest ones, throughout the mass-table. These approach and their
extensions such as the Random Phase Approximation (RPA) and Generator Coordinate Method (GCM)
give access to observables from ground state, excited states and large-amplitude collective motion of the
nuclei. Furthermore, the mean-field gives a natural interpretation of the nuclear configurations through
the shapes of the system in its intrinsic frame.
It is well established that a correct description of the ground states of deformed heavy nuclei, rotational
bands, isomeric states energies and fission barriers is strongly correlated with the value of the surface
energy coefficient a_surf and also the surface symmetry energy coefficient a_ssym .
A first step in the direction of a better description of shapes of heavy nuclei was recently achieved
with the construction of the SLy5sX series of Skyrme-EDFs and more specifically with the SLy5s1
parameterisation. The systematically improved agreement for deformation properties of heavy nuclei
achieved with SLy5s1 compared to widely-used parameterisations such as SLy5, however, comes
at the expense of a significant increase of mass residuals.
In this presentation, I will show that a slight modification of the fit protocol together with the
inclusion of the often-neglected two-body contribution to the center-of-mass correction in functional
greatly improve the results for shapes, barriers heights and binding energies. I will present the details
of the fit protocol and show a set of selected results. It turns out that completely omitting the center-
of-mass correction as sometimes done for parameterisations aiming at nuclear dynamics is similarly
problematic as using the standard recipe where only the one-body part is kept. I will also discuss how
the statistical error bars on the parameters of the functional propagate on calculated quantities such as
fission barriers.
