Related papers: N=4 Extended MSSM
The connection between the scales of $ {\rm SU} (2)\times {\rm U} (1) $ gauge symmetry breaking and supersymmetry breaking is didactically displayed in the framework of a T.O.Y. (Theory Overestimating Yukawas) model, a version of the $…
We investigate the phenomenology of minimal four-family MSSM supergravity theories containing an additional generation of heavy fermions along with their superpartners. We demand: gauge coupling constant unification at high energy scales;…
The knowledge of the stability condition of the electroweak (EW) vacuum is of the greatest importance for our understanding of beyond Standard Model (BSM) physics. It is widely believed that new physics that lives at very high energy scales…
We investigate the standard model (SM) with the extension of a charged scalar having fractional electromagnetic charge of $-1/3$ unit and with lepton and baryon number violating couplings at tree level. Without directly taking part in the…
Running of gauge couplings in the MSSM from a unified value at high energies leads to a successful prediction of the weak mixing angle. Supersymmetric models at the TeV scale may contain further hints of high scale physics, such as the…
We discuss extensions of the Standard Model through extending the electroweak gauge symmetry. An extended electroweak symmetry requires a list of extra fermionic and scalar states. The former is necessary to maintain cancellation of gauge…
We perform an analysis of the vacuum stability of the neutral scalar potential of the $\mu$-from-$\nu$ Supersymmetric Standard Model ($\mu\nu$SSM). As an example scenario, we discuss the alignment-without-decoupling limit of the…
We consider electroweak symmetry breaking in supersymmetric models with an extra non-anomalous U(1)' gauge symmetry and an extra standard-model singlet scalar S. For appropriate charges the U(1)' forbids an elementary mu term, but an…
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 re-evaluate the constraints on the parameter space of the minimal supersymmetric standard model from tunneling to charge- and/or color-breaking minima, taking into account thermal corrections. We pay particular attention to the region…
We propose extended 3HDM and 4HDM models where the SM gauge symmetry is enlarged by the spontaneously broken $S_4$ group, the preserved $Z_2$ and broken $Z_4$ cyclic symmetries. Each model has three active $SU(2)$ scalar doublets, in…
We consider the minimal U(1)' extension of the standard model (SM) with the classically conformal invariance, where an anomaly-free U(1)' gauge symmetry is introduced along with three generations of right-handed neutrinos and a U(1)' Higgs…
We propose a theoretical justification for the anomalous Higgs couplings without extending the particle content of the Standard Model, but rather assuming different realization of the electroweak symmetry and the representation of the Higgs…
We study a supersymmetric extension of the vector-like lepton scenario, such that the vacuum instability induced by large lepton Yukawa couplings is lifted by the presence of superpartners at or below the TeV scale. In order to preserve the…
In this paper we consider a set of soft supersymmetry breaking terms within the NMSSM which leads to a small hierarchy between the supersymmetry breaking scale and the electroweak scale. Specifically only the gaugino masses and the soft…
We consider the requirements that all coupling constants remain perturbative and the electroweak vacuum metastable up to the Planck scale in high-scale thermal leptogenesis, in the context of a type-I seesaw mechanism. We find a large…
We study a model with an exotic new sector strongly coupled to the Higgs boson, in which supersymmetry is introduced to protect the quartic coupling from a large running and avoid potential vacuum stability problem. The fermionic components…
Motivated by the coupling unification problem, we propose a novel extension of the Minimal Supersymmetric Standard Model. One of the predictions of this extension is existence of new states neutral under SU(3)_c X SU(2)_w but charged under…
We make a complete analysis of the Yukawa coupling unification in SU(5) extensions of the MSSM in the framework of the radiative symmetry breaking scenario. Both logarithmic and finite threshold corrections of sparticles have been included…
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…