Recent Progress in the Theory of Nuclear Forces

TL;DR

This paper reviews recent advances in chiral effective field theory for nuclear forces, highlighting successes and unresolved issues such as renormalization and convergence of many-body forces.

Contribution

It summarizes progress in deriving nuclear forces up to N3LO and discusses ongoing challenges in the theoretical framework.

Findings

Successful derivation of two-, three-, and four-nucleon forces up to N3LO

Application of chiral EFT to nuclear few- and many-body systems

Identification of open issues like renormalization and convergence

Abstract

During the past two decades, it has been demonstrated that chiral effective field theory represents a powerful tool to deal with nuclear forces in a systematic and model-independent way. Two-, three-, and four-nucleon forces have been derived up to next-to-next-to-next-to-leading order (N3LO) and (partially) applied in nuclear few- and many-body systems---with, in general, a good deal of success. This may suggest that we are finally done with the nuclear force problem; but that would be too optimistic. There are still some pretty basic open issues that have been swept under rug and, finally, need our full attention, like the proper renormalization of the two-nucleon potential. Moreover, the order-by-order convergence of the many-body force contributions is at best obscure at this time.