Theory Seminar: Towards ab-initio optical potentials for elastic scattering of He6 off protons
Speaker: Charlotte Elster, Ohio University
Location: Auditorium
Time: 13:00
The calculation and derivation of microscopic optical potentials for calculating scattering observables for elastic scattering from spin-zero nuclei has a long tradition. So-called microscopic `full-folding' models based on a nuclear density matrix and a fully-off-shell two-nucleon t-matrix have been developed mainly for closed shell nuclei heavier than Oxygen-16. Constructing microscopic optical potentials for the Helium-6 isotope poses a two-fold challenge: First, Helium-6 as well as Helium-8 are not closed-shell nuclei. Second, Helium-6 is a loosely bound nucleus consisting of an alpha-core and two valence neutrons. To address the first challenge, the Watson optical potential has been extended to incorporate the open-shell structure of Helium-6 and Helium-8. Both those effects on the differential cross section and the polarization are calculated for a set of energies, including 71~MeV/nucleon. For considering the second challenge, an optical potential based on the Watson first order multiple scattering ansatz is extended to accommodate the internal dynamics of a cluster model for the Helium-6 nucleus. Differential cross sections and analyzing powers are calculated for a set of energies and discussed.