Title:  Effective field theory, factorization and renormalization: neutrino interactions, the Fermi function and more

Abstract:  Precisely calculating differences between muon- and electron-neutrino interactions is difficult, but is vital for correctly interpreting neutrino oscillation experiments. I describe recent progress with powerful quantum field theory techniques to precisely determine the ratio of νe and νµ cross sections.  The beta decay Fermi function describes electron propagation in a nuclear Coulomb field, and accounts for QED radiative corrections that are enhanced at small electron velocity β or large nuclear charge Z.  Such enhanced corrections impact a variety of processes in and beyond the Standard Model, ranging from nuclear beta decay to dark matter annihilation signals.  I present the field theory factorization formula for the Fermi function and discuss implications for precision measurements.