Applying Twisted Boundary Conditions for Few-body Nuclear Systems

TL;DR

This paper introduces twisted boundary conditions in nuclear lattice EFT to accurately determine few-body nuclear binding energies from finite-volume calculations, reducing computational costs.

Contribution

It develops and verifies a method using twisted boundary conditions, including a three-body analogue of i-periodic angles, to improve finite-volume energy extrapolations.

Findings

Finite-volume effects can be minimized with appropriate twists.

Reliable extraction of infinite-volume energies from modest volumes.

Three-body i-periodic twist angles eliminate leading finite-volume effects.

Abstract

We describe and implement twisted boundary conditions for the deuteron and triton systems within finite-volumes using the nuclear lattice EFT formalism. We investigate the finite-volume dependence of these systems with different twists angles. We demonstrate how various finite-volume information can be used to improve calculations of binding energies in such a framework. Our results suggests that with appropriate twisting of boundaries, infinite-volume binding energies can be reliably extracted from calculations using modest volume sizes with cubic length $L\approx8-14$ fm. Of particular importance is our derivation and numerical verification of three-body analogue of `i-periodic' twist angles that eliminate the leading order finite-volume effects to the three-body binding energy.