Speaker
Description
First generation quark Yukawa couplings are notoriously difficult to measure. Various proposals for their measurement is based on multi-boson production such as Higgs pair production, Higgs off-shell production or triple V production. Those probes will not be able though to probe modifications below factors of order hundred. Given this in this talk, I will discuss how large the light quark Yukawa couplings can actually become in UV models. Concretely, large enhancements can be achieved in models with pairs of vector-like quarks. These models generate operators in Standard Model Effective Field Theory, both at tree-level and one-loop, that also modify, for example, the couplings of the quarks to the electroweak bosons. Therefore, constraints from electroweak precision tests and Higgs physics arise. Nevertheless, those models allow for rather large enhancement factors motivating to search for modifications in light quark Yukawa couplings in multi-boson processes.