Renormalization of nuclear chiral effective field theory with non-perturbative leading order interactions

TL;DR

This paper investigates the renormalization of nucleon-nucleon interactions in chiral effective field theory, emphasizing non-perturbative leading-order effects and their impact on power counting and cutoff dependence.

Contribution

It introduces new renormalization constraints for non-perturbative leading-order interactions in chiral EFT, improving the understanding of cutoff independence and power counting.

Findings

Renormalization constraints are more severe for non-perturbative LO interactions.

Cutoff dependence is reduced with the new constraints.

Chiral expansion convergence varies across different partial waves.

Abstract

We extend the renormalizability study of the formulation of chiral effective field theory with a finite cutoff, applied to nucleon-nucleon scattering, by taking into account non-perturbative effects. We consider the nucleon-nucleon interaction up to next-to-leading order in the chiral expansion. The leading-order interaction is treated non-perturbatively. In contrast to the previously considered case when the leading-order interaction was assumed to be perturbative, new features related to the renormalization of the effective field theory are revealed. In particular, more severe constraints on the leading-order potential are formulated, which can enforce the renormalizability and the correct power counting for the next-to-leading order amplitude. To illustrate our theoretical findings, several partial waves in the nucleon-nucleon scattering, $^3P_0$, $^3S_1-{^3D_1}$ and $^1S_0$ are analyzed numerically. The cutoff dependence and the convergence of the chiral expansion for those channels are discussed.