Quantified impact of the Pauli exclusion principle on the nucleus-nucleus interaction

The Pauli exclusion principle plays a crucial role as a pillar of many-body quantal systems comprised of fermions. It also induces a “Pauli repulsion” in the interaction between heavy ions. It has been shown in [1] that the Pauli repulsion widens the nucleus-nucleus potential barrier, thus hindering sub-barrier fusion. To extend this picture, we use the Pauli kinetic energy (PKE) obtained by studying the nuclear localization function [2]. This approach is employed in both the static density constrained frozen Hartree-Fock and in the dynamic density constrained time-dependent Hartree-Fock microscopic methods. Significant effects are seen at first contact of the reaction nuclei and deep inside the fusion barrier. Furthermore, varying effects are seen for dynamic proton/neutron contributions inside the barrier, seen as an effect of multinucleon transfer. The PKE is shown to make a significant contribution to statically and dynamically derived nuclear interaction potentials.

[1] - Phys. Rev. C95, 031601 (2017)

[2] - https://arxiv.org/abs/2105.05245