Preliminary Results on Improving Determination of the Nucleon Axial Form Factor with Lattice QCD

The nucleon axial form factor (F_A(Q^2)) is a vital input for calculating the charged current quasielastic cross section for long-baseline neutrino experiments such as T2K & DUNE. Lattice Quantum Chromodynamics (LQCD), a non-perturbative way of solving QCD by discretizing space and time, is a leading method for calculating the axial form factor. Recent LQCD results yield an axial vector coupling at 1% level uncertainty and in agreement with experiment. However, there is a discrepancy in the axial form factor at high momentum transfer when comparing LQCD to experiment as well as between different experiments. This poster presents work towards improving understanding of the axial form factor with LQCD, using one ensemble and a large range of time separations to probe excited state contamination at low times. We achieve stability in the value of the form factor across different numbers of fit states and time ranges of interest, and are planning a more complete study into excited state contamination using more ensembles in the near future.