Particle Physics Seminar: QED corrections for fundamental physics in the face of nuclei

Abstract:

Searches for physics beyond the Standard Model often require percent-level precision, and must include QED radiative corrections. When an experiment involves nuclei (e.g. neutrino experiments, LDMX, Mu2e, or direct detection experiments) further complications arise due to the large nuclear charge, and the fact that nuclei themselves introduce new scales into the problem (nuclear radius, binding energies, etc.). 

I will outline an effective field theory (EFT) that disentangles nuclear scales from the particle physics we care about. The EFT provides a rigorous formalism for QED corrections in the presence of nuclei accounting for charged and neutral currents, structure dependence, nuclear excited states, and gauge invariance.  As an application of the EFT formalism, I will discuss (in some detail) radiative corrections for the extraction of $V_{ud}$ from superallowed beta decays. I will close by highlighting potential applications for BSM physics, including tests of CKM unitarity, backgrounds for muon conversion, and light dark matter.
 

Seminar Organizers: Dr. Michael Geller & Dr. Adi Ashkanzi