<i>Ab initio</i>many-body calculations of nucleon-nucleus scattering

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 the Pauli principle. We outline technical details and present phase-shift results for neutron scattering on $^{3}\mathrm{H}$, $^{4}\mathrm{He}$, and $^{10}\mathrm{Be}$ and proton scattering on $^{3,4}\mathrm{He}$, using realistic nucleon-nucleon ($\mathit{NN}$) potentials. Our $A=4$ scattering results are compared to earlier ab initio calculations. We find that the CD-Bonn $\mathit{NN}$ potential in particular provides an excellent description of nucleon-$^{4}\mathrm{He}S$-wave phase shifts. In contrast, the experimental nucleon-$^{4}\mathrm{He}P$-wave phase shifts are not well reproduced by any $\mathit{NN}$ potential we use. We demonstrate that a proper treatment of the coupling to the $n\text{\ensuremath{-}}^{10}\mathrm{Be}$ continuum is successful in explaining the parity-inverted ground state in $^{11}\mathrm{Be}$.