Ground state energy of dilute neutron matter at next-to-leading order in lattice chiral effective field theory

TL;DR

This paper calculates the ground state energy of dilute neutron matter at next-to-leading order using lattice chiral effective field theory, employing improved actions and Monte Carlo methods to analyze systems of 8, 12, and 16 neutrons.

Contribution

It introduces an improved spin- and isospin-projected leading-order action enabling perturbative NLO corrections in lattice chiral EFT for dilute neutron matter.

Findings

Ground state energies computed for 8, 12, and 16 neutrons.

Density range from 2% to 10% of nuclear density covered.

Reduced estimated errors with improved action.

Abstract

We present lattice calculations for the ground state energy of dilute neutron matter at next-to-leading order in chiral effective field theory. This study follows a series of recent papers on low-energy nuclear physics using chiral effective field theory on the lattice. In this work we introduce an improved spin- and isospin-projected leading-order action which allows for a perturbative treatment of corrections at next-to-leading order and smaller estimated errors. Using auxiliary fields and Euclidean-time projection Monte Carlo, we compute the ground state of 8, 12, and 16 neutrons in a periodic cube, covering a density range from 2% to 10% of normal nuclear density.