Precision nucleon-nucleon potential at fifth order in the chiral expansion

TL;DR

This paper develops a fifth-order chiral nucleon-nucleon potential that significantly improves phase shift descriptions, demonstrating good convergence and supporting a new uncertainty quantification method, advancing precision nuclear force modeling.

Contribution

The paper introduces a fifth-order chiral nucleon-nucleon potential with improved accuracy and confirms the effectiveness of a novel uncertainty quantification approach.

Findings

Enhanced description of nucleon-nucleon phase shifts at fifth order

Natural size of higher-order corrections confirms good convergence

Supports a new method for quantifying theoretical uncertainties

Abstract

We present a nucleon-nucleon potential at fifth order in chiral effective field theory. We find a substantial improvement in the description of nucleon-nucleon phase shifts as compared to the fourth-order results of Ref. [E. Epelbaum, H. Krebs, U.-G. Mei{\ss}ner, arXiv:1412.0142 [nucl-th]]. This provides clear evidence of the corresponding two-pion exchange contributions with all low-energy constants being determined from pion-nucleon scattering. The fifth-order corrections to nucleon-nucleon observables appear to be of a natural size which confirms the good convergence of the chiral expansion for nuclear forces. Furthermore, the obtained results provide strong support for the novel way of quantifying the theoretical uncertainty due to the truncation of the chiral expansion proposed in Ref. [E. Epelbaum, H. Krebs, U.-G. Mei{\ss}ner, arXiv:1412.0142 [nucl-th]]. Our work opens up new perspectives for precision ab initio calculations in few- and many-nucleon systems and is especially relevant for ongoing efforts towards a quantitative understanding the structure of the three-nucleon force in the framework of chiral effective field theory.