Restless pions from orbifold boundary conditions: an explicit construction for noise reduction in lattice QCD

TL;DR

This paper introduces an explicit algorithm using orbifold boundary conditions to significantly improve the signal-to-noise ratio in lattice QCD calculations of nuclear forces, enabling more precise first-principles studies.

Contribution

It develops a practical algorithm for implementing orbifold boundary conditions in lattice QCD, enhancing noise reduction without requiring new gauge configurations.

Findings

Improved signal-to-noise ratio in multibaryon correlators.

Explicit algorithm compatible with existing gauge configurations.

Discussion of finite volume effects and phase shift calculations.

Abstract

The exponentially decreasing signal to noise ratio in multibaryon correlators is the main obstacle to a first principles, QCD-based calculation of the nuclear force. Recently, we have proposed an orbifold boundary condition ("restless pions") that can dramatically improve this matter. Here we develop the idea further by proposing an explicit algorithm that can be used with purely periodic, "off the shelf" gauge configurations. We also discuss finite volume corrections with the new boundary conditions and the use of the "Luscher formula'' for the phase shifts.