26 Novembre – Thesis defense - Duy Duc Dao
10 h Seminar room - CENBG (Gradignan)
Hartree-Fock approximation for deformed nuclei with a general two-nucleon potential and pairing correlations with a consistent residual interaction.
In this work, we have developed the Hartree-Fock (HF) approximation in momentum space for deformed nuclei with a general nucleon-nucleon (NN) potential. The structure of such a potential has been investigated in momentum space from its symmetries. Its constructions has been realized in a tensorial separable momentum-spin-isospin representation. Moreover, to treat low-momentum interactions, we have implemented the Similarity Renormalization Group approach. Three momentum representations have been studied: the plane-wave, the partial-wave and the confined plane-wave. The numerical implementation has been validated against an existing HF-Skyrme code in the harmonic oscillator basis. We have found that the confined plane-wave basis provides many advantages over the two others, namely: flexible construction of symmetry-adapted bases, efficient calculation of matrix elements (nuclear, Coulomb and center of mass kinetic correction) and optimization in ressources (time and memory). This basis is characterized by two parameters: the confinement box size (cube) which can be essentially related to the nuclear radius and a single-particle momentum cut-off which is directly linked to the cut-off in relative momentum of the interaction. Bulk properties of some spherical and deformed even-even nuclei in the mass region A < 100 have been calculated with recently developed NN potentials. The resulting residual interaction has been derived to study pairing correlations within the Highly Truncated Diagonalization Approach (HTDA). In particular, the question of the convergence with the model space has been addressed.
