Chiral three-nucleon forces and pairing in nuclei

TL;DR

This paper investigates the impact of chiral three-nucleon forces on nuclear pairing, revealing significant repulsive effects and showing that combined two- and three-nucleon interactions explain about 70% of experimental pairing gaps.

Contribution

First systematic study of nuclear pairing including chiral three-nucleon forces using microscopic calculations at first order.

Findings

Chiral three-nucleon forces contribute significantly to pairing interactions.

Two- and three-nucleon forces explain about 70% of experimental pairing gaps.

Repulsive effects from three-nucleon forces are substantial.

Abstract

We present the first study of pairing in nuclei including three-nucleon forces. We perform systematic calculations of the odd-even mass staggering generated using a microscopic pairing interaction at first order in chiral low-momentum interactions. Significant repulsive contributions from the leading chiral three-nucleon forces are found. Two- and three-nucleon interactions combined account for approximately 70% of the experimental pairing gaps, which leaves room for self-energy and induced interaction effects that are expected to be overall attractive in nuclei.