Systematics in nucleon matrix element calculations

Abstract

The current status of calculations of simple nucleon structure observables is reviewed, with a focus on the axial charge. A major challenge is the combination of an exponentially decaying signal-to-noise ratio and the need for large source-sink separations to eliminate excited-state contributions; efforts to understand and deal with this problem are the focus of the largest section of this review. Finite-volume effects and chiral extrapolation are also briefly discussed.

Comments: 15 pages, 7 figures. Talk presented at the 36th International Symposium on Lattice Field Theory (Lattice 2018), 22-28 July, 2018, Michigan State University, East Lansing, MI, USA