The Higgs data and the Decoupling Limit

TL;DR

This paper explores how the properties of the Higgs boson can resemble the Standard Model predictions in various theoretical scenarios, including the decoupling limit and cases with nearly degenerate scalar states, within the two-Higgs doublet model framework.

Contribution

It analyzes the decoupling limit and potential deviations from SM-like Higgs behavior in the two-Higgs doublet model, considering unresolved scalar states.

Findings

Higgs properties approach SM predictions in the decoupling limit.

Nearly degenerate scalar states can mimic SM-like Higgs signals.

Implications for current and future Higgs data are discussed.

Abstract

The Higgs data analyzed by the ATLAS and CMS Collaborations suggest that the scalar state discovered in 2012 is a Standard Model (SM)--like Higgs boson. Nevertheless, there is still significant room for Higgs physics beyond the Standard Model. Many approaches to electroweak symmetry breaking possess a decoupling limit in which the properties of the lightest CP-even Higgs scalar approach those of the SM Higgs boson. In some cases, an apparent SM-like Higgs signal can also arise in a regime that may not be governed by the decoupling limit. One such scenario can be realized if the observed Higgs signal is a result of two unresolved nearly-mass-degenerate scalar states. The general two-Higgs doublet model provides a useful framework for studying the decoupling limit and possible departures from SM-like Higgs behavior. The implications for current and future Higgs data are briefly considered.