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

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.