Ab initio calculations of low-energy nuclear scattering using confining potential traps

Abstract

A recently modified method to enable low-energy nuclear scattering results to be extracted from the discrete energy levels of the target-projectile clusters confined by harmonic potential traps is tested. We report encouraging results for neutron--$\alpha$ and neutron--${}^{24}\mathrm{O}$ elastic scattering from analyzing the trapped levels computed using two different ab initio nuclear structure methods. The $n$--$\alpha$ results have also been checked against a direct ab initio reaction calculation. The $n$--${}^{24}\mathrm{O}$ results demonstrate the approach's applicability for a large range of systems provided their spectra in traps can be computed by ab initio methods. A key ingredient is a rigorous understanding of the errors in the calculated energy levels caused by inevitable Hilbert-space truncations in the ab initio methods.

Comments: Close to the published version; ancillary files attached; modifications: (1) the naming of the method is changed in the title and text, (2) a concentrated discussion of error sources is included in the main text, and (3) comparisons with existing methods are included in the supplemental material