Preliminary Lattice QCD Study of nn → ppee Matrix Element for Neutrinoless Double-Beta Decay

Several ongoing experiments are searching for a signal of neutrinoless double-beta decay, which would indicate that the neutrino is a Majorana fermion. The bounds on decay rate observed in these experiments depend on neutrino properties as well as nuclear structure, and current systematic uncertainties from nuclear shell models are a significant contribution to the uncertainty in the range of excluded parameter space. As such, additional theoretical understanding of the nuclear matrix elements contributing to double-beta decay rates would be desirable. We aim to perform a preliminary study of the matrix element of the transition of a dineutron to a diproton. While this particular transition is unphysical, it serves as a proof of concept of the study of matrix elements relevant for 0νββ on the lattice.