Physics Theory Seminar with Emilie Passemar on Axial Form Factor of the Nucleon and Neutrino-Nucleus Cross Sections

Long-baseline experiments of the near future, DUNE in the US and Hyper-Kamiokande in Japan, plan to determine the neutrino mass hierarchy and the amount of CP violation, by measuring subtle three-flavor interference effects in oscillations. The success of this experimental program will crucially rely in our ability to accurately model neutrino cross sections off nuclear targets. A major source of uncertainty in the analysis of neutrino-nucleus interactions is the axial vector form factor of the nucleon. Unlike the nucleon vector form factors, which can be directly measured with electron scattering, the functional form of the axial form factor, F_A(Q²), is much less well known. In this talk, we will review our current knowledge of the axial form factor and focus on the recent considerable progress in the lattice QCD  determination of F_A(Q²), for the momentum transfer values up to Q² ~ 1 GeV². We will investigate how these lattice results map into predicted neutrino cross sections. Specifically, we deconstruct the predicted double-differential cross sections at MiniBOONE and MINERVA in terms of the contributions from the different Q² ranges. Our analysis should help guide further lattice calculations, as well as the modeling of nuclear effects, for which accurate understanding of the single-nucleon interaction is an essential prerequisite.

Zoom link available upon request at physics@wustl.edu.
Post-docs and students' Q&A with the speaker starts at 2:15 pm. Contact Garrett King for the Q&A Zoom link.