Chiral symmetry and peripheral neutron-$\alpha$ scattering

TL;DR

This paper demonstrates that low-energy peripheral neutron-alpha scattering can effectively probe long-range three-nucleon forces, highlighting the importance of chiral symmetry in understanding few-body nuclear interactions.

Contribution

It introduces ab initio quantum Monte Carlo calculations incorporating chiral effective field theory to analyze neutron-alpha scattering, emphasizing the role of two-pion exchange three-nucleon forces.

Findings

Long-range three-nucleon forces significantly affect neutron-alpha D-wave phase shifts.

Chiral symmetry provides predictive power in few-body nuclear physics.

The study opens new avenues for constraining three-nucleon interactions.

Abstract

We propose and demonstrate that peripheral neutron-$\alpha$ scattering at low energies can serve as a sensitive and clean probe of the long-range three-nucleon forces. To this aim, we perform {\it ab initio} quantum Monte Carlo calculations using two- and three-nucleon interactions derived in chiral effective field theory up to third expansion order. We show that the longest-range three-nucleon force stemming from the two-pion exchange plays a crucial role in the proper description of the neutron-$\alpha$ $D$-wave phase shifts. Our Letter reveals the predictive power of chiral symmetry in the few-body sector and opens a new direction for probing and constraining three-nucleon forces.