Physics Models for Extended Higgs Sector Searches

This page lists the physics models that can be used to perform searches for additional Higgs boson measurements at the LHC, when the SM-like Higgs boson should be accounted for in the data.

Two Higgs Models

These models are for the case where there are just Two Higgs bosons, one of which is the SM-like Higgs boson that was discovered at the LHC. The two Higgs models are implemented in the python file TwoHiggsModels.py. For each of these models, we assume that the SM-like Higgs boson has mass specified by MH_SM, while the additional boson has mass MH.

You can produce the model by including the following option in the text2workspace.py command:

-P HiggsAnalysis.CombinedLimit.TwoHiggsModels:model

	model	--PO	POIs	Description
Two Higgs bosons	twoHiggsUnconstrained	N/A	r, r_SM	The SM-like Higgs boson signal strength will be r_SM and its mass will be assumed to be MH_SM (default value 125.8), while the additional Higgs boson signal strength will be scaled by r and assumed to have mass MH.
Singlet Mixing Model	singletMixing	--PO BSMDecays,--PO UseVisibleMu	r,BR_BSM	Without any options, the SM like Higgs boson will have signal strength r, while the additional Higgs boson is scaled by 1-r and BR_BSM will not be a POI. If the option BSMDecays is included, the additional boson's signal strength will be r(1-BR_BSM) and the SM like Higgs boson will have signal strength of 1-r. If the option UseVisibleMu is included too, then instead, the additional Higgs boson will get a signal strength r while the SM one will have 1-r(1-BR_BSM).
Singlet Mixing Model for Exclusions	singletMixingInvisible	--PO BSMDecays	r,x,BR_BSM	The SM like Higgs boson will be scaled by r*x while the additional boson is scaled by r*(1-x). If the option BSMDecays is included, then BR_BSM is also a POI and the additional Higgs boson signal strength is scaled accounting for this BSM branching fraction r*(1-x)*(1-BR_BSM).
Two Higgs bosons with \(c_{V}\), \(c_{F}\) couplings	twoHiggsCvCf	N/A	CV, CF	Both Higgs bosons signal strengths scale accoring to the coupling to vector bosons CV and fermions CF where the scaling is determined for each contributing production/decay vertex. In this case, the additioal boson is assumed to follow the same coupling structure (i.e the SM like Higgs boson couplings).

Two Higgs Doublet Models

In these models, the couplings of the SM-like Higgs boson are modified according to the type of 2HDM with parameters \(\cos(\beta-\alpha)\) and \(\tan\beta\). The two Higgs doublet models are implemented in the python file AdditionalModels.py. In this model, the Higgs boson mass is MH, and it can be promoted to a POI by including the option --PO higgsMassRange=[low,high].

You can produce the model by including the following option in the text2workspace.py command:

-P HiggsAnalysis.CombinedLimit.AdditionalModels:model_name

	model	--PO	POIs	Description
2HDM Type-1	twohdm	--PO thdmtype=1	cosbma,tanbeta	The couplings of the Higgs boson to fermions and vector bosons are modified by the parameters cosbma (\(\cos(\beta-\alpha)\)) and tanbeta (\(\tan\beta\)). The couplings dependencies are \(\kappa_V = \sqrt(1-\cos^{2}(\beta-\alpha))\), \(\kappa_{u}=\kappa_{d}=\cos(\alpha)/\sin(\beta)\).
2HDM Type-2	twohdm	--PO thdmtype=2	cosbma,tanbeta	The couplings of the Higgs boson to fermions and vector bosons are modified by the parameters cosbma (\(\cos(\beta-\alpha)\)) and tanbeta (\(\tan\beta\)). The couplings dependencies are \(\kappa_V = \sqrt(1-\cos^{2}(\beta-\alpha))\), \(\kappa_{u}=\cos(\alpha)/\sin(\beta)\), \(\kappa_{d}=-\sin(\alpha)/\cos(\beta)\).
2HDM Type-3	twohdm	--PO thdmtype=3	cosbma,tanbeta	The couplings of the Higgs boson to quarks, leptons and vector bosons are modified by the parameters cosbma (\(\cos(\beta-\alpha)\)) and tanbeta (\(\tan\beta\)). The couplings dependencies are \(\kappa_V = \sqrt(1-\cos^{2}(\beta-\alpha))\), \(\kappa_{u}=\kappa_{d}=\cos(\alpha)/\sin(\beta)\), \(\kappa_{l}=-\sin(\alpha)/\cos(\beta)\).
2HDM Type-4	twohdm	--PO thdmtype=4	cosbma,tanbeta	The couplings of the Higgs boson to quarks, leptons and vector bosons are modified by the parameters cosbma (\(\cos(\beta-\alpha)\)) and tanbeta (\(\tan\beta\)). The couplings dependencies are \(\kappa_V = \sqrt(1-\cos^{2}(\beta-\alpha))\), \(\kappa_{u}=\kappa_{l}=\cos(\alpha)/\sin(\beta)\), \(\kappa_{d}=-\sin(\alpha)/\cos(\beta)\).

Fermiophobic Higgs Model

This model is for the case where the additional Higgs boson does not couple to fermions. The fermiophobic Higgs model is implemented in the python file HiggsFermiophobic.py. In this model, the Higgs boson mass is MH, and it can be promoted to a POI by including the option --PO higgsMassRange=[low,high].

You can produce the model by including the following option in the text2workspace.py command:

-P HiggsAnalysis.CombinedLimit.HiggsFermiophobic:model_name

	model	--PO	POIs	Description
Fermiophobic Higgs	fp	N/A	r	The Higgs boson signal strength will be r for any production/decay that involves vector boson couplints only. The branching ratios are recalculated assuming no Higgs boson couplings to fermions.