Speaker
Description
While the Higgs boson’s couplings to massive gauge bosons and third-generation fermions align with Standard Model predictions, those to the light quarks and the electron remain experimentally elusive. In this talk, I will classify and investigate simplified UV models that can significantly enhance Yukawa couplings of light fermions. These models generate operators in Standard Model Effective Field Theory at tree level and one-loop, constrained by electroweak precision observables, Higgs data, flavor physics, and direct searches. Considering all bounds, we identify the models in which first-generation quark Yukawa couplings can be enhanced by up to several hundred times their Standard Model value, while the Higgs couplings to charm (strange) can increase by factors of a few (few tens). Given the importance of electroweak precision data, we discuss projections for future measurements at the FCC-ee collider. Additionally, we explore the potential for significant deviations in the electron Yukawa coupling, assessing how future intensity-frontier measurements, including the anomalous moment of the electron, can provide competitive probes relative to a dedicated FCC-ee run at the Higgs pole mass.
