The SU(2)xU(1) electroweak model describes well the Higgs mechanism via a spontaneously broken symmetry. This requires a single doublet of complex scalar fields. But does nature follow this minimal version or does it require a multi-Higgs sector?. The minimal SM consists of one complex isospin Higgs doublet which after symmetry breaking predicts one physical neutral scalar. Nevertheless, one can find extensive leterature concerning extended models i.e. the non-minimal SM. Extended Higgs sectors with additional doublets/triplets always require exotic Higgs bosons with electric charge (H±) and zero tree-level couplings to gauge bosons (A0). Moreover, in some extended models can exhibits 'fermiophobia' i.e. zero tree-level couplings to fermions. The most theoretically favorable non-minimal Higgs sectors are those that contain only doublet representations. These are know as two-Higgs-doublet models (2HDM) for which there are four distinct versions. The model type-I is the only model that can display fermiophobia which makes it the subject of our search.

In short, a Higgs model incorporating two doublets of complex scalar fields generates five scalar Higgs bosons, three of which are neutral. For type-I models, and for certain choices of the model parameters, one of these neutral scalars provides mass only to the fermions and the other couples exclusively to the bosons, i.e. is a “fermiophobic” Higgs boson. The fermiophobia can only arise in certain Higgs models, and in particular are not predicted by the minimal supersymmetric model (MSSM). Therefore, a possible existence of a fermiophobic Higgs will be an evidence against MSSM.