Related papers: Higher-order scalar interactions and SM vacuum sta…
The talk is devoted to the problem of stability of the Standard Model vacuum. The effective potential for the Higgs field, which can potentialy exhibit additional, deeper minimum, is considered as a convenient tool for addressing the…
Light, electrically charged vector-like `leptons' with order one Yukawa couplings can enhance the Higgs to diphoton decay rate, as is suggested by measurements of the signal strength \mu_{\gamma\gamma} by ATLAS and CMS. However, the large…
The unification of gauge coupling constants in the minimal supersymmetric model (MSSM) is unaffected at the one-loop level by the inclusion of additional mass-degenerate SU(5) multiplets. Perturbativity puts an upper limit on the number of…
Within the framework of the Standard Model, the scale of electroweak symmetry breaking is unstable to radiative corrections. We discuss two broad classes of models of new physics (one with a strongly interacting and the other with a…
We present evidence for new phases of the Standard Model Higgs potential. We study the Standard Model physical trajectory accounting for the Higgs curvature mass with the mass-dependent functional renormalisation group. New unstable and…
In this research, we investigate the vacuum structure of an extended standard model with a $U(1)_D$ global symmetry. The scalar sector consists of two $SU(2)$ doublets as well as one complex singlet and one real singlet, resulting in a more…
In this paper we examine the stability of scalar perturbations in nonsingular models which emerge from an interacting vacuum component. The analysis developed in this paper relies on two phenomenological choices for the energy exchange…
We investigate the stability of the electroweak vacuum for two-Higgs doublet models with a supersymmetric UV completion. The supersymmetry breaking scale is taken to be of the order of the grand unification scale. We first study the case…
We investigate the vacuum stability as well as the gravitational corrections in extensions of the Standard Model featuring a new complex scalar, and two Dirac fermions for different choices of the hypercharge of the scalar and one of the…
The recently introduced energy-saving extension of the sub-optimal sliding mode control allows for control-off phases during the convergence to second-order equilibrium. This way, it enables for a lower energy consumption compared to the…
The plethora of scalar fields participating in the formulation of a softly broken supersymmetric theory can threat the stability of the standard vacuum. The generic situation is twofold. Directions in scalar field space may exist along…
We propose a generalization of the Standard Model (SM) by adding two real gaugesinglets S1, S2. The field S1 will improve the strength of the electroweak phase transition (EWPT). Imposing a Z2 symmetry on the field S2 makes this field a…
The condition of unification of gauge couplings in the minimal supersymmetric standard model provides successful predictions for the weak mixing angle as a function of the strong gauge coupling and the supersymmetric threshold scale. In…
At high energy the standard model possesses conformal symmetry at the classical level. This is reflected at the quantum level by relations between the different beta functions of the model. These relations are known as the Weyl consistency…
We consider renormalisable models extended in the scalar sector by a generic scalar field in addition to the standard model Higgs boson field, and work out the effective theory for the latter in the decoupling limit. We match the full…
We investigate a minimal $U(1)'$ extension of the Standard Model with one extra complex scalar and generic gauge charge assignments. We use a type-I seesaw mechanism with three heavy right handed neutrinos to illustrate the constraints on…
We examine the possible extension of the parameter space of the minimal supersymmetric extension of the Standard Model (MSSM), as expressed via the renormalization-group equations in terms of universal soft supersymmetry-breaking terms at…
From the point of view of the gauge hierarchy problem, introducing an intermediate scale in addition to TeV scale and the Planck scale ($M_{\rm Pl} = 2.4 \times 10^{18}\,{\rm GeV}$) is unfavorable. In that way, a gauge coupling unification…
A fine tuned hierarchy between a strongly coupled high energy compositeness scale and a much lower chiral symmetry breaking scale is a requisite ingredient in many models of dynamical electroweak symmetry breaking. Using a nonperturbative…
It has been suggested recently that in a consistent theory any Minkowski vacuum must be exactly stable. As a result, a large class of theories that in ordinary treatment would appear sufficiently long-lived, in reality make no sense. In…