Related papers: Constraining New Models with Precision Electroweak…
While it is often stated that the notion of electroweak (EW) naturalness in supersymmetric models is subjective, fuzzy and model-dependent, here we argue the contrary: electroweak naturalness can be elevated to a {\it principle} which is…
We provide a set of theoretical constraints on models in which the Standard Model field content is extended by vector-like fermions and in some cases also by a real scalar singlet. Our approach is based on the study of electroweak vacuum…
We explore in detail the Higgs phenomenology that results in a model where right-handed neutrinos have a mass scale of the order of the electroweak scale. In this model all scales arise from spontaneous symmetry breaking, and this is…
Precision electroweak data are generally believed to constrain the Higgs boson mass to lie below approximately 190 GeV at 95% confidence level. The standard Higgs model is, however, trivial and can only be an effective field theory valid…
I review how electroweak precision observables can be used to constrain the Higgs boson mass and the strong coupling constant. Implications for physics beyond the Standard Model are also addressed.
A strongly first-order electroweak phase transition is a necessary requirement for Electroweak Baryogenesis. We investigate the plausibility of obtaining a strong phase transition in a Two-Higgs-Doublet Model of type II with a minimal…
The one-loop radiative correction in an ultraviolet (UV) complete electroweak (EW) model without a Higgs particle is calculated. The $\rho$ parameter determining the ratio of the charged to neutral currents is derived for the dominant top…
The Higgs potential of the standard model with an additional real Higgs singlet is studied in order to examine if it may allow the strongly first order electroweak phase transition. It is found that there are parameter values for which this…
Electroweak precision observables allow stringent tests of the Standard Model at the quantum level and imply interesting bounds on the mass of the Higgs boson through higher-order loop effects. Very significant constraints come especially…
We analyse effective potential around the electroweak (EW) scale in the Standard Model extended with a heavy scalar doublet. We show that the additional scalars can have a strong impact on vacuum stability. Although the additional heavy…
We study bounds on Higgs boson masses from perturbative unitarity in the Georgi-Machacek model, whose Higgs sector is composed of a scalar isospin doublet, a real and a complex isospin triplet fields. This model can be compatible with the…
We obtain limits on generic vector-like leptons at the TeV scale from electroweak precision tests. These limits are complementary to the ones obtained from lepton flavour violating processes. In general, the quality of the global…
We calculate the tree-level expressions for the electroweak precision observables in the SU(5)/SO(5) littlest Higgs model. The source for these corrections are the exchange of heavy gauge bosons, explicit corrections due to non-linear…
This is a report of the Electroweak Symmetry Breaking and Beyond the Standard Model Working Group which was prepared for the Division of Particles and Fields Committee for Long Term Planning. We study the phenomenology of electroweak…
We present an update of the global Standard Model (SM) fit to electroweak precision data under the assumption that the new particle discovered at the LHC is the SM Higgs boson. In this scenario all parameters entering the calculations of…
We consider Loryons, particles beyond the Standard Model that receive a significant fraction of their masses from electroweak symmetry breaking, in the context of a two Higgs doublet model. Using scalar Loryons in the the $[1,1]$, $[1,3]$…
The status of various precisely measured electroweak parameters is reviewed. Natural relations among them are shown to constrain the Higgs mass, m_H, via quantum loop effects to relatively low values. A comparison with direct Higgs searches…
Phase transitions induced by high temperatures and strong magnetic fields are investigated in the Standard model. The consistent effective potential including the one-loop and ring diagram contributions is calculated and investigated for…
Electroweak Baryogenesis is a particularly attractive theoretical scenario, since it relies on physics which can be tested at present high energy collider facilities. Within the Standard Model, it has been shown that the requirement of…
We discuss electroweak constraints on TeV scale extensions of the standard model. To obtain model-independent results, effective theory approach is adopted. Constraints are given on arbitrary linear combinations of a set of dimension-6…