Quantum Monte Carlo Calculations with Chiral Effective Field Theory Interactions

TL;DR

This paper introduces the first quantum Monte Carlo calculations using local chiral effective field theory interactions, demonstrating systematic convergence and providing benchmarks for nuclear matter studies.

Contribution

It develops local chiral EFT interactions suitable for QMC, enabling nonperturbative calculations and systematic order-by-order analysis in nuclear physics.

Findings

Systematic convergence observed in chiral EFT orders.

Excellent agreement between perturbative and QMC results for softer interactions.

Provides benchmarks for nuclear matter calculations.

Abstract

We present the first quantum Monte Carlo (QMC) calculations with chiral effective field theory (EFT) interactions. To achieve this, we remove all sources of nonlocality, which hamper the inclusion in QMC calculations, in nuclear forces to next-to-next-to-leading order. We perform auxiliary-field diffusion Monte Carlo (AFDMC) calculations for the neutron matter energy up to saturation density based on local leading-order, next-to-leading order, and next-to-next-to-leading order nucleon-nucleon interactions. Our results exhibit a systematic order-by-order convergence in chiral EFT and provide nonperturbative benchmarks with theoretical uncertainties. For the softer interactions, perturbative calculations are in excellent agreement with the AFDMC results. This work paves the way for QMC calculations with systematic chiral EFT interactions for nuclei and nuclear matter, for testing the perturbativeness of different orders, and allows for matching to lattice QCD results by varying the pion mass.