Isovector Axial Form Factor of the Nucleon from Lattice QCD

Abstract

The isovector axial form factor of the nucleon plays a key role in interpreting data from long-baseline neutrino oscillation experiments. We present a lattice QCD calculation of this form factor, introducing a new method to directly extract its z-expansion from lattice correlators. Our final parameterization of the form factor, which extends up to spacelike virtualities of 0.7 GeV^2 with fully quantified uncertainties, agrees with previous lattice calculations but is significantly less steep than neutrino-deuterium scattering data suggests.

Proceeding for the 39th International Symposium on Lattice Field Theory (Lattice2022), 8th-13th August 2022, Bonn, Germany