Nuclear Seminar

Calculations with Finite-range forces in Neutron-rich Nuclei

Dr. Nicolas Schunck
Oak Ridge National Laboratory
University of Tennessee

Monday, April 23, 2007   4:00 p.m.   NSH 124
(Refreshments served prior to seminar in NSH 124)

With the on-going development of Radioactive Beam Facilities, proton- or neutron-rich nuclei have come under more intense scrutiny. From a theoretical point of view, these systems present a number of interesting features. First of all they are characterized by a very large isospin, whose influence on the density functional is not very well-known. Moreover their Fermi level is quite close to the continuum threshold, and residual interactions such as pairing correlations can scatter particles into it. The interplay of the nuclear system with the continuum is therefore a crucial ingredient of all serious theoretical approaches, and this has been the main argument to call for the development of more appropriate techniques than those used in stable nuclei. However, the description of pairing correlations in such systems, e.g. in Skyrme HFB approaches, has always been somewhat empirical. We therefore developed a technique to extend the realm of HFB calculations with finite-range forces like the Gogny force to weakly-bound nuclei. In addition to include continuum effects, this technique is amenable to go beyond the mean-field and to give a precise measure of the true role of the continuum in ground-state properties of atomic nuclei. I will describe this technique, present some of the results we obtained and discuss critically the extent of continuum effects in weakly-bound nuclei.