Non-perturbative three-nucleon simulation using chiral lattice EFT

TL;DR

This paper presents a non-perturbative lattice EFT simulation of the three-nucleon system at N3LO, accurately determining three-nucleon forces and properties without relying on perturbation theory, and comparing results with other lattice EFT approaches.

Contribution

It introduces a non-perturbative lattice EFT method for three-nucleon systems at N3LO, determining low-energy constants directly from nuclear observables.

Findings

Accurate ground state energies for triton and helion.

Charge radii calculations consistent with experimental data.

No significant effect of smearing regularization observed.

Abstract

We study the three-nucleon system at next-to-next-to-next-to-leading order ($\mathrm{N^3LO}$) in the framework of chiral effective field theory (EFT) on the lattice. Our calculations do not rely on a perturbative treatment of subleading contributions to the nuclear forces. For the two-nucleon potential, we apply the previously developed $\mathrm{N^3LO}$ lattice interaction. For the leading contribution to the three-nucleon force, we determine the two low-energy constants (LECs) in the contact interactions by adjusting the ground state energy and half-life of triton, where the latter employs the nuclear axial current at $\mathrm{N^2LO}$ in chiral EFT. Additionally, the ground state energy of helion and the charge radii of the two considered nuclei are computed. No effect of the smearing regularization in the three-nucleon contact interaction is observed here. We compare our results with recent lattice-EFT calculations that are based on a potential tuned to light and medium-mass nuclei using the wave-function-matching technique to circumvent the Monte-Carlo sign problem.