Sterile Higgs Boson

To address the “little hierarchy problem,” we introduce two extra scalar fields neutral under the standard model gauge symmetry on top of the standard model. One linear combination of them has an almost flat potential, and so it can dynamically compensate the large Higgs mass parameter, while its small negative mass parameter can play the role of the electroweak symmetry breaking source. Thus the smallness of its mass parameter is responsible for the relatively small Higgs vacuum expectation value compared to a cut-off energy scale of the standard model. This scenario should eventually be embedded e.g. in a supersymmetric model, where the small mass parameters of the neutral singlets can be explained by employing both the gravity- and gauge-mediated supersymmetry breaking mechanisms. Their mixing angles with the Higgs boson can be suppressed enough (∼ 10−2), avoiding the phenomenological constraints. The mass of the lighter scalar field is of order sub-electroweak scale (∼ 10 GeV), when the heavier one is above TeV scale (∼ 5 TeV).