Elementary Goldstone Higgs Boson and Dark Matter

We investigate a perturbative extension of the Standard Model featuring elementary pseudo-Goldstone Higgs and dark matter particles. These are two of the five Goldstone bosons parametrising the SU(4)/Sp(4) coset space. They acquire masses, and therefore become pseudo-Goldstone bosons, due to the embedding of the Yukawa and the electroweak gauge interactions that do not preserve the full SU(4) symmetry. At the one-loop order the top corrections dominate and align the vacuum in the direction where the Higgs is mostly a pseudo-Goldstone boson. Because of the perturbative and elementary nature of the theory, the quantum corrections are precisely calculable. The remaining pseudo-Goldstone boson is identified with the dark matter candidate because it is neutral with respect to the Standard Model and stable. By a direct comparison with the Large Hadron Collider experiments, the model is found to be phenomenologically viable. Furthermore the dark matter particle leads to the observed thermal relic density while respecting the most stringent current experimental constraints.Comment: 26 pages, 6 figures. Revised version to match the published on

High energy fate of the minimal Goldstone Higgs boson

We consider a minimal model where the Higgs boson arises as an elementary pseudo-Nambu-Goldstone boson. The model is based on an extended scalar sector with global SO(5)/SO(4) symmetry. To achieve the correct electroweak symmetry-breaking pattern, the model is augmented either with an explicit symmetry-breaking term or an extra singlet scalar field. We consider separately both of these possibilities. We fit the model with the known particle spectrum at the electroweak scale and extrapolate to high energies using renormalization group. We find that the model can remain stable and perturbative up to the Planck scale provided that the heavy beyond standard model scalar states have masses in a narrow interval around 3 TeV.Peer reviewe

Theory and phenomenology of the elementary Goldstone Higgs boson

We show, via a careful analytical and numerical analysis, that a pseudo-Goldstone nature of the Higgs is naturally embodied by an elementary realization that also serves as ultraviolet completion. Renormalizability married to perturbation theory allows us to precisely determine the quantum corrections of the theory while permitting us to explore the underlying parameter space. By characterizing the available parameter space of the extended Higgs sector we discover that the preferred electroweak alignment angle is centered around θ≃0.02, corresponding to the Higgs chiral symmetry breaking scale f≃14 TeV. The latter is almost 60 times higher than the Standard Model electroweak scale. However, due to the perturbative nature of the theory, the spectrum of the enlarged Higgs sector remains in the few TeV energy range. We also analyze precision constraints and the relevant phenomenological aspects of the theory

High energy fate of the minimal Goldstone Higgs boson

We consider a minimal model where the Higgs boson arises as an elementary pseudo-Nambu-Goldstone boson. The model is based on an extended scalar sector with global SO(5)/SO(4) symmetry. To achieve the correct electroweak symmetry-breaking pattern, the model is augmented either with an explicit symmetry-breaking term or an extra singlet scalar field. We consider separately both of these possibilities. We fit the model with the known particle spectrum at the electroweak scale and extrapolate to high energies using renormalization group. We find that the model can remain stable and perturbative up to the Planck scale provided that the heavy beyond standard model scalar states have masses in a narrow interval around 3 TeV

Baryogenesis via elementary Goldstone Higgs relaxation

We extend the relaxation mechanism to the elementary Goldstone Higgs framework. Besides studying the allowed parameter space of the theory, we add the minimal ingredients needed for the framework to be phenomenologically viable. The very nature of the extended Higgs sector allows to consider very flat scalar potential directions along which the relaxation mechanism can be implemented. This fact translates into wider regions of applicability of the relaxation mechanism when compared to the Standard Model Higgs case. Our results show that if the electroweak scale is not fundamental but radiatively generated it is possible to generate the observed matter-antimatter asymmetry via the relaxation mechanism

Elementary Goldstone Higgs boson and dark matter

We investigate a perturbative extension of the Standard Model featuring elementary pseudo-Goldstone Higgs and dark matter particles. These are two of the five Goldstone bosons parametrizing the SU(4)/Sp(4) coset space. They acquire masses, and therefore become pseudo-Goldstone bosons, due to the embedding of the Yukawa and the electroweak gauge interactions that do not preserve the full SU(4) symmetry. At the one-loop order, the top corrections dominate and align the vacuum in the direction where the Higgs is mostly a pseudo-Goldstone boson. Because of the perturbative and elementary nature of the theory, the quantum corrections are precisely calculable. The remaining pseudo-Goldstone boson is identified with the dark matter candidate because it is neutral with respect to the Standard Model and stable. By a direct comparison with the Large Hadron Collider experiments, the model is found to be phenomenologically viable. Furthermore the dark matter particle leads to the observed thermal relic density while respecting the most stringent current experimental constraints

Vacuum alignment with and without elementary scalars

We systematically elucidate differences and similarities of the vacuum alignment issue in composite and renormalizable elementary extensions of the Standard Model featuring a pseudo-Goldstone Higgs. We also provide general conditions for the stability of the vacuum in the elementary framework, thereby extending previous studies of the vacuum alignment