A determination of the weak neutral-current axial-vector form factor

We use a combination of lattice QCD calculations of the strange-quark electromagnetic form factors and a phenomenological parametrization of the F₁and F₂ electromagnetic form factors, to obtain the weak neutral-current axial form factor from a fit to MiniBooNE and BNL (anti)-neutrino-nucleon elastic scattering differential cross-section data. We thereby obtain a value for the weak axial charge, and the strange-quark contribution to the proton spin. We conclude with prospects for fully ab initial calculations of the form factor within lattice QCD.