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Ian Bentley

University of Notre Dame
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Investigations of the Nuclear Symmetry Energy (Wigner Energy) and Mapping of Fermionic to Bosonic Deformation Energy Surfaces

Two unrelated topics of research will be discussed, which are of interest for nuclear structure and which have some potential applications for astrophysical calculations. The work on both of these topics is based on the calculation of the equilibrium deformation of nuclei. The background of the mixed micro-macro method used in the deformation calculations will be included and comparsions will be made with standard Moeller Nix deformations.

It has been long observed that the symmetry energy in nuclei has a linear term and is proportional to T(T+X), where T is the isospin and X is a constant. The application of isovector and isoscalar pairing using a simple pure pairing Hamiltonian on several level calculations will be discussed. The role of deformations is critical for reproducing the observed fluctuations of this constant. Suggestions for simple ways to include isovector pairing in mass models will been included.

Additionally, a coherent state technique is used to generate an Interacting Boson Model (IBM) Hamiltonian energy surface that simulates a mean field energy surface. The method presented here has some significant advantages over previous work. Specifically, that this can be a completely predictive requiring no a priori knowledge of the IBM parameters. The technique allows for the prediction of the low lying energy spectra and electromagnetic transition rates which are of astrophysical interest.

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