Quantum Monte Carlo in Configuration Space with Three-Nucleon Forces

TL;DR

This paper extends the Configuration-Interaction Monte Carlo method to include three-nucleon forces in neutron matter, enabling efficient calculations of its properties using non-local interactions in momentum space.

Contribution

The work introduces a novel extension of the CIMC method to incorporate three-nucleon interactions via the normal-ordered two-body approximation in neutron matter.

Findings

Equation of state results consistent with other many-body methods.

Predictions for momentum distribution and static structure factor.

Demonstrates efficiency of CIMC with non-local interactions.

Abstract

Neutron matter, through its connection to neutron stars as well as systems like cold atom gases, is one of the most interesting yet computationally accessible systems in nuclear physics. The Configuration-Interaction Monte Carlo (CIMC) method is a stochastic many-body technique allowing to tackle strongly coupled systems. In contrast to other Quantum Monte Carlo methods employed in nuclear physics, the CIMC method can be formulated directly in momentum space allowing for an efficient use of non-local interactions. In this work we extend CIMC method to include three-nucleon interactions through the normal-ordered two-body approximation. We present results for the equation of state of neutron matter in line with other many-body calculations that employ low resolution chiral interactions, and provide predictions for the momentum distribution and the static structure factor.