Particle Physics Seminar, Brian Henning, Berkeley, "What do precision Higgs measurements buy us?"

Sep 26, 2014, 4:00 pm5:00 pm
Jadwin 111


Event Description
The exciting discovery of the Higgs boson finally gives us a chance to experimentally probe the strangest particle in the Standard Model. At the forefront of questions is whether or not there is new physics beyond the Standard Model that explains the unnatural and mysterious properties of the Higgs boson. In this talk, we examine the sensitivities of future precision Higgs measurements and electroweak observables in probing BSM physics. We argue that effective field theory (EFT) is the appropriate framework for future precision studies and develop several useful tools for this study. In particular, we present a manifestly gauge covariant method of calculating one-loop effective actions to determine Wilson coefficients in the EFT. We also provide a direct mapping between Wilson coefficients and precision observables. Taken together, these provide a useful dictionary to easily translate between UV models and experimental parameters. Within this EFT framework, we examine well-motivated test cases. One of these test cases is a tree-level example due to a singlet scalar field that enables the first-order electroweak phase transition for baryogenesis. Another is a one-loop example due to scalar top in the MSSM. We find both Higgs and electroweak measurements are sensitive probes of these cases.