Multi-nucleon matrix elements on the lattice with the Feynman-Hellmann theorem

TL;DR

This paper demonstrates a novel lattice QCD approach using the Feynman-Hellmann theorem to compute multi-nucleon structure functions, specifically the deuteron’s forward Compton structure function, paving the way for systematic multi-nucleon studies.

Contribution

It introduces a new method combining Feynman-Hellmann techniques with lattice QCD to efficiently calculate multi-nucleon matrix elements, addressing computational challenges.

Findings

First calculation of the deuteron’s $ ext{F}_2$ structure function moment on the lattice.

Development of optimized techniques for multi-nucleon Wick contraction calculations.

Establishment of a systematic framework for future multi-nucleon structure studies.

Abstract

This work presents the first calculation of the lowest moment of the forward Compton structure function $\mathcal{F}_2$ for a multi-nucleon deuteron-like state using Feynman-Hellmann lattice QCD techniques. Using this result as a prototypical example, we chart a course for the systematic study of multi-nucleon structure by building on techniques developed to optimise the computation of the factorially increasing number of Wick contraction terms required to calculate multi-nucleon matrix elements via lattice QCD.