Related papers: Custodial Naturalness
The idea of naturalness, as originally conceived, refers only to the finite renormalization of the Higgs boson mass induced by the introduction of heavier states. In this respect, naturalness is still a powerful heuristic principle in model…
In supersymmetric theories with a strong conformal sector, soft supersymmetry breaking at the TeV scale naturally gives rise to confinement and chiral symmetry breaking at the same scale. We investigate models where such a sector…
It is pointed out that the top-quark and Higgs masses and the Higgs VEV satisfy with great accuracy the relations 4m_H^2=2m_T^2=v^2, which are very special and reminiscent of analogous ones at Argyres - Douglas points with enhanced…
Motivated by the stability of the electroweak Higgs vacuum we consider the possibility that the Standard Model might work up to large scales between about $10^{10}$ GeV and close to the Planck scale. A plausible scenario is an emergent…
We describe a composite Higgs scenario in which a cosmological relaxation mechanism naturally gives rise to a hierarchy between the weak scale and the scale of spontaneous global symmetry breaking. This is achieved through the scanning of…
A large value of the cosmological constant (CC) is induced in the Standard Model (SM) of Elementary Particle Physics because of Spontaneous Symmetry Breaking. To provide a small value of the observable CC one has to introduce the vacuum…
In models with extended scalar sectors consisting of multiple Higgs doublets that trigger spontaneous electroweak symmetry breaking, it might be expected that the abundance of dimensionful quadratic couplings in the scalar potential could…
We present a mechanism that allows a large Higgsino mass without large fine-tuning. The Higgs is a pseudo Nambu-Goldstone boson (PNGB) of the global symmetry breaking pattern $SO(5) \to SO(4)$. Because of the PNGB nature of the light Higgs,…
In any theory it is unnatural if the observed parameters lie very close to special values that determine the existence of complex structures necessary for observers. A naturalness probability, P, is introduced to numerically evaluate the…
We present a model that extends the electroweak gauge symmetry of the Standard Model in a non-universal way to $SU(2)_{L}^{\prime}\times U(1)_X \times SU(2)_{L}^{q_3}\times SU(2)_R^{\ell_3}$. This symmetry is spontaneously broken to…
We construct a simple theory in which the fine-tuning of the standard model is significantly reduced. Radiative corrections to the quadratic part of the scalar potential are constrained to be symmetric under a global U(4) x U(4)' symmetry…
We investigate a new scenario of the two Higgs doublet model, where the current experimental data for the electroweak rho parameter and those for the Higgs boson couplings can be simultaneously explained. In this scenario, the two Higgs…
We introduce a toy model implementing the proposal of using a custodial symmetry to protect the Z b_L bbar_L coupling from large corrections. This "doublet-extended standard model" adds a weak doublet of fermions (including a heavy partner…
We consider a hidden sector with a vectorlike confining gauge theory like QCD with $N_{h,c}$ colors and $N_{h,f}$ light quarks ${\cal Q}_h$ in the hidden sector. Then a scale $\Lambda_H$ would be generated by dimensional transmutation, and…
In the standard model (SM), the $\rho$ parameter is equal to 1 and the ratio $\lambda_{WZ}$ of Higgs $\to ZZ$ and Higgs $\to WW$ is also equal to 1 at the tree level. When going beyond the SM with more than one types of Higgs…
Motivated by LHC results, we modify the usual criterion for naturalness by ignoring the uncomputable power divergences. The Standard Model satisfies the modified criterion ('finite naturalness') for the measured values of its parameters.…
We investigate cosmological phase transitions in various composite Higgs models consisting of four-dimensional asymptotically-free gauge field theories. Each model may lead to a confinement-deconfinement transition and a phase transition…
For decades, the unnaturalness of the weak scale has been the dominant problem motivating new particle physics, and weak-scale supersymmetry has been the dominant proposed solution. This paradigm is now being challenged by a wealth of…
We study the occurrence of a strong first-order electroweak phase transition in composite Higgs models. Minimal constructions realising this scenario are based on the coset SO(6)/SO(5) which delivers an extended Higgs sector with an…
In this article, we investigate the $Y=0$ $SU(2)$ scalar triplet and $Z_2$-odd scalar singlet extension of the Standard Model (SM). Here, the triplet charged Higgs boson decays to $ZW^\pm$, breaking the custodial symmetry at the tree-level,…