Form Factors in Higgs Couplings from Physics Beyond the Standard Model

TL;DR

This paper investigates how physics beyond the Standard Model can cause momentum-dependent modifications in Higgs couplings, using model-dependent calculations to predict effects observable in collider kinematics.

Contribution

It provides a detailed computation of form factors for various BSM scenarios affecting Higgs couplings, enabling simulation of their experimental signatures.

Findings

Form factors vary across models, affecting Higgs kinematic distributions.

Sensitivity to BSM effects depends on off-shellness flow in couplings.

Different channels have varying sensitivity to specific BSM scenarios.

Abstract

We consider the momentum-dependent effects in Higgs couplings generated by physics beyond the standard model. We take a model-dependent approach, in which we can fully compute the non-local effects from physics not directly reachable by the LHC energy. We consider several scenarios, including composite Higgs models, additional scalars, and the continuum contributions of a quasi-conformal sector, as examples. For each specific model, we are able to obtain the form factor, with which it is then possible to fully simulate the effects in kinematics distributions. The momentum-dependent effects appear as a consequence of off-shellness in the process. We show how the sensitivity of different channels to the various models depends on how the flow of off-shellness appears in the Higgs couplings.