Few-nucleon systems with state-of-the-art chiral nucleon-nucleon forces

TLDR: In this article, the authors apply improved nucleon-nucleon potentials up to fifth order in chiral effective field theory, along with a new analysis of the theoretical truncation errors to study nucleon deuteron scattering and selected low-energy observables in $ −3, −4, −5, −6, −7, −8, −9, −10.

Abstract: We apply improved nucleon-nucleon potentials up to fifth order in chiral effective field theory, along with a new analysis of the theoretical truncation errors to study nucleon-deuteron $(\mathrm{N}d)$ scattering and selected low-energy observables in $^{3}\mathrm{H},^{4}\mathrm{He}$, and $^{6}\mathrm{Li}$. Calculations beyond second order differ from experiment well outside the range of quantified uncertainties, providing truly unambiguous evidence for missing three-nucleon forces within the employed framework. The sizes of the required three-nucleon-force contributions agree well with expectations based on Weinberg's power counting. We identify the energy range in elastic $\mathrm{N}d$ scattering best suited to study three-nucleon-force effects and estimate the achievable accuracy of theoretical predictions for various observables.