Quantum Monte Carlo Calculations of Light Nuclei Using Chiral Potentials

TL;DR

This paper introduces the first Green's function Monte Carlo calculations of light nuclei using chiral effective field theory interactions, showing systematic improvements and the importance of three-body forces.

Contribution

It demonstrates the feasibility of using local chiral potentials in quantum Monte Carlo calculations for light nuclei and explores perturbative behavior at different chiral orders.

Findings

Systematic improvement in binding energies with increasing chiral order.

Higher-order corrections are more perturbative for softer interactions.

Three-body forces are essential for accurate reproduction of experimental data.

Abstract

We present the first Green's function Monte Carlo calculations of light nuclei with nuclear interactions derived from chiral effective field theory up to next-to-next-to-leading order. Up to this order, the interactions can be constructed in a local form and are therefore amenable to quantum Monte Carlo calculations. We demonstrate a systematic improvement with each order for the binding energies of $A=3$ and $A=4$ systems. We also carry out the first few-body tests to study perturbative expansions of chiral potentials at different orders, finding that higher-order corrections are more perturbative for softer interactions. Our results confirm the necessity of a three-body force for correct reproduction of experimental binding energies and radii, and pave the way for studying few- and many-nucleon systems using quantum Monte Carlo methods with chiral interactions.