Abstract
It has been almost a decade since the first hints of the Higgs boson discovery began to emerge from CERN, making a review of our updated expectations for the Higgs boson properties, in light of New Physics models, timely. In this review I attempt to draw connections between modified Higgs boson couplings and the big questions that broad classes of New Physics models aim to answer. Questions considered include whether the Higgs boson is composite and whether a new space-time supersymmetry exists. The goal is to present these topics, framed in reference to the Higgs boson, in a conceptually driven manner and, to make them accessible to a relatively broad audience, without a great deal of technicality.
Highlights
Protons were revealed to have innards too—in this case, quarks and gluons—but only after a period of denial, in which some believed that they were too curious to exist and must, instead, be some mathematical trickery
The degree to which the Higgs boson is composite is quantified by the degree to which the Higgs couplings deviate from the SM values
It might seem that all of the Higgs couplings to SM fields are unmodified since the Higgs boson does not mix with φ, and all SM processes, such as the Higgs decay width into fermions (h → f f ), are unmodified
Summary
To frame the subject of Higgs couplings in BSM theories, it is important to emphasize that couplings, which usually are interpreted as the coefficients of operators in the Lagrangian, are not themselves observables. Renormalizability is important here because it means that even if this interaction is generated at high scales, far above the electroweak scale in some more fundamental theory, this interaction will remain relevant at lower energies In this model, it might seem that all of the Higgs couplings to SM fields are unmodified since the Higgs boson does not mix with φ, and all SM processes, such as the Higgs decay width into fermions (h → f f ), are unmodified. The point is that when discussing Higgs coupling modifications in an EFT, we must be careful to specify the basis being used since, physical observables such as cross sections and decay widths are immutable and unambiguous, terms in Lagrangians are not. Having discussed questions of fine-tuning, the EFT basis, and the physical meaning of Higgs couplings within the context of this one simple model, I turn to connections between Higgs couplings and a variety of fundamental questions in Higgs physics
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
