Ab initio many-body calculations of nucleon-nucleus scattering

TL;DR

This paper introduces a new ab initio many-body method combining the resonating-group approach with realistic interactions to accurately describe bound and scattering states in light nuclei, with promising results for phase shifts and continuum coupling.

Contribution

The paper presents a novel ab initio method that unifies bound and scattering state calculations in light nuclei using realistic interactions and the resonating-group technique.

Findings

CD-Bonn potential accurately reproduces 4He S-wave phase shifts.

P-wave phase shifts in 4He are not well matched by current NN potentials.

Coupling to the n-10Be continuum explains the 11Be ground state parity inversion.

Abstract

We develop a new ab initio many-body approach capable of describing simultaneously both bound and scattering states in light nuclei, by combining the resonating-group method with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters. This approach preserves translational symmetry and Pauli principle. We outline technical details and present phase shift results for neutron scattering on 3H, 4He and 10Be and proton scattering on 3He and 4He, using realistic nucleon-nucleon (NN) potentials. Our A=4 scattering results are compared to earlier ab initio calculations. We find that the CD-Bonn NN potential in particular provides an excellent description of nucleon-4He S-wave phase shifts. On the contrary, the experimental nucleon-4He P-wave phase shifts are not well reproduced by any NN potential we use. We demonstrate that a proper treatment of the coupling to the n-10Be continuum is successful in explaining the parity-inverted ground state in 11Be.