Higgs phenomenology in the Stealth Doublet Model

Abstract

We analyze a model for the Higgs sector with two scalar doublets and a $Z_2$ symmetry that is manifest in the Yukawa sector but broken in the potential. Thus, one of the doublets breaks the electroweak symmetry and has tree-level Yukawa couplings to fermions, whereas the other doublet has no vacuum expectation value and no tree-level couplings to fermions. Since the $Z_2$ parity is broken the two doublets can mix, which leads to a distinct and novel phenomenology. This Stealth Doublet Model can be seen as a generalization of the Inert Doublet Model with a broken $Z_2$ symmetry. We outline the model and present constraints from theory, electroweak precision tests and collider searches, including the recent observation of a Higgs boson at the LHC. The charged scalar $H^{\pm }$ and the CP-odd scalar $A$ couple to fermions at one-loop level. We compute the decays of $H^{\pm }$ and $A$ and in particular the one-loop decays $A\to f\bar{f}$, $H^{\pm }\to f{\bar{f}}^{\prime }$, $H^{\pm }\to W^{\pm }Z$ and $H^{\pm }\to W^{\pm }\gamma$. We also describe how to calculate and renormalize such processes in our model. We find that if one of $H^{\pm }$ or $A$ is the lightest scalar, $H^{\pm }\to W^{\pm }\gamma$ or $A\to b\bar{b}$ are typically their respective dominating decay channels. Otherwise, the dominating decays of $H^{\pm }$ and $A$ are into a scalar and a vector. Due to the absence of tree-level fermion couplings for $H^{\pm }$ and $A$, we consider pair production and associated production with vector bosons and scalars at the LHC. If the parameter space of the model that favors $H^{\pm }\to W^{\pm }\gamma$ is realized in Nature, we estimate that there could be a considerable amount of such events in the present LHC data.

40 pages, 25 figures. Version 4. Minor updates, references added. Version to appear in PRD

References in corpus (14)

• Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC
• Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
• FeynRules - Feynman rules made easy
• Improved Naturalness with a Heavy Higgs: An Alternative Road to LHC Physics
• Measurement of the properties of a Higgs boson in the four-lepton final state
• Observation of the diphoton decay of the Higgs boson and measurement of its properties
• Measurement of Higgs boson production in the diphoton decay channel in $pp$ collisions at center-of-mass energies of 7 and 8 TeV with the ATLAS detector
• Measurements of Higgs boson production and couplings in the four-lepton channel in $pp$ collisions at center-of-mass energies of 7 and 8 TeV with the ATLAS detector
• Basis-independent methods for the two-Higgs-doublet model II. The significance of tan(beta)
• Consistency of the Two Higgs Doublet Model and CP violation in top production at the LHC
• Low-mass fermiophobic charged Higgs phenomenology in two-Higgs-doublet models
• Charged Higgs Bosons decays H^\pm \to W^\pm (γ, Z) revisited
• Two Higgs Pair Heterotic Vacua and Flavor-Changing Neutral Currents
• Searching for a CP-odd Higgs via a pair of gauge bosons at the LHC

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• Low-mass fermiophobic charged Higgs phenomenology in two-Higgs-doublet models
• Charged Higgs boson in the $W^{\pm }$ Higgs channel at the Large Hadron Collider
• The $W\gamma$ decay of the elusive charged Higgs boson in the two-Higgs-doublet model with vectorlike fermions
• ATLAS Diboson Excesses from the Stealth Doublet Model
• Light (and darkness) from a light hidden Higgs
• Chemical freeze-outs of strange and non-strange particles and residual chemical non-equilibrium