Recent results in chiral effective field theory for the NN system

TL;DR

This paper reviews recent advances in chiral effective field theory for the nucleon-nucleon system, emphasizing a systematic, renormalization-group invariant approach grounded in QCD symmetries for nuclear physics applications.

Contribution

It introduces a systematic, perturbative, and renormalization-group invariant formulation of chiral EFT for NN interactions, improving upon previous cutoff-dependent methods.

Findings

Successful implementation of a renormalization-group invariant EFT for NN interactions

Demonstration of a perturbative expansion consistent with QCD symmetries

Enhanced theoretical foundation for nuclear structure and reactions

Abstract

I describe recent progress towards a theory of the NN force which captures the consequences of QCD's chiral symmetry and the pattern of its breaking, and is formulated as an expansion in a ratio of low and high mass scales, M_{lo}/M_{hi}. This "chiral effective field theory" of the NN system is a firm foundation for explorations of nuclear structure and reactions that are grounded in QCD's low-energy symmetries. While calculations that use a ChiPT expansion for the NN potential have proven very successful, they can only be used with a narrow range of momentum-space cutoffs, which leaves the expansion parameter for observable quantities somewhat murky. Here we seek a truly systematic effective field theory for the NN amplitude, that is manifestly renormalization-group invariant at each order in a demonstrably perturbative expansion.