Anomalous Higgs Couplings
M. C. Gonzalez-Garcia
TL;DR
The paper analyzes how new physics in the electroweak sector can modify Higgs couplings by adopting a linearly realized $SU(2)_L \times U(1)_Y$ effective Lagrangian with eleven dimension-six operators. It maps how these operators alter Higgs production, decay, and gauge-boson interactions, and uses precision electroweak data and direct gauge-boson measurements from LEP and the Tevatron to constrain the operator coefficients and the new-physics scale $\Lambda$. A key finding is that certain operators can substantially enhance rare Higgs decays like $H\rightarrow \gamma\gamma$ and $H\rightarrow Z\gamma$, providing clean collider signatures, while precision data strongly restricts many operators’ coefficients. The results guide Higgs searches and help quantify the possible impact of new physics in the electroweak sector on Higgs phenomenology, establishing bounds on $f_n/\Lambda^2$ that translate into limits on the scale of new interactions.
Abstract
We review the effects of new effective interactions on the Higgs boson phenomenology. New physics in the electroweak bosonic sector is expected to induce additional interactions between the Higgs doublet field and the electroweak gauge bosons leading to anomalous Higgs couplings as well as to anomalous gauge-boson self-interactions. Using a linearly realized $SU(2)_L \times U(1)_Y$ invariant effective Lagrangian to describe the bosonic sector of the Standard Model, we review the effects of the new effective interactions on the Higgs boson production rates and decay modes. We summarize the results from searches for the new Higgs signatures induced by the anomalous interactions in order to constrain the scale of new physics in particular at CERN LEP and Fermilab Te vatron colliders.