Related papers: The hierarchy problem and the vacuum stability in …
We consider a minimal extension of the Standard Model (SM), which leads to unification of the SM coupling constants, breaks electroweak symmetry dynamically by a new strongly coupled sector and leads to novel dark matter candidates. In this…
We update the constraints on the minimal model of dark matter, where a stable real scalar field is added to the standard model Lagrangian with a renormalizable coupling to the Higgs field. Once we fix the dark matter abundance, there are…
We study extensions of the Twin Higgs model that solve the Hierarchy problem and simultaneously address problems of the large- and small-scale structures of the Universe. Besides naturally providing dark matter (DM) candidates as the…
We consider a simple extension of the Standard Model by the addition of N real scalar gauge singlets $\vp$ that are candidates for Dark Matter. By collecting theoretical and experimental constraints we determine the space of allowed…
The constituents of dark matter are still an unresolved puzzle. Several Beyond Standard Model (BSM) Physics offer suitable candidates. In this study here we consider the Two Higgs Doublet model augmented with a complex scalar singlet…
The Higgs-portal model with a singlet scalar Dark Matter particle is one of the simplest extensions to the Standard Model that can reproduce the relic density. Unfortunately this model is strongly constrained by direct and indirect DM…
We study an extension of the Standard Model featuring a hidden sector that consists of a new scalar charged under a new SU$(N)_D$ gauge group, singlet under all Standard Model gauge interactions, and coupled with the Standard Model only via…
The inability to predict neutrino masses and the existence of the dark matter are two essential shortcomings of the Standard Model. The Higgs Triplet Model provides an elegant resolution of neutrino masses via the seesaw mechanism. We show…
We examine a model with multiple scalar fields to see whether it is possible to reduce the fine- tuning of the SM Higgs mass without introducing low scale top partners. Our approach may be regarded as a generalization of the condition…
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 present a new solution to the electroweak hierarchy problem. We introduce $N$ copies of the Standard Model with varying values of the Higgs mass parameter. This generically yields a sector whose weak scale is parametrically removed from…
We extend the two-Higgs doublet models of Type I and Type II by adding a real gauge-singlet scalar S dark matter candidate (2HDMS models). We impose theoretical constraints deriving from perturbativity, stability, unitarity and correct…
In this work, we implement a complex scalar Dark Matter (DM) candidate in a $U(1)_{B-L}$ gauge extension of the Standard Model. The model contains three right handed neutrinos with different quantum numbers and a rich scalar sector, with…
We investigate the electroweak vacuum stability in an extended version of the Standard Model which incorporates two additional singlet scalar fields and three right handed neutrinos. One of these extra scalars plays the role of dark matter…
We consider an extension of the Higgs sector in the standard model (SM) with six Higgs doublets. The gauge couplings are unified without supersymmetry in this model. The lightest of the extra Higgs particles, being stabilized by a discrete…
The two-Higgs-doublet model augmented with a complex scalar singlet (2HDMS) is a well-motivated candidate for Beyond Standard Model (BSM) Physics. We investigate the dark matter phenomenology of the 2HDMS with the complex scalar singlet as…
Constraints from precision electroweak measurements reveal no evidence for new physics up to 5 - 7 TeV, whereas naturalness requires new particles at around 1 TeV to address the stability of the electroweak scale. We show that this "little…
We discuss a minimal extension to the standard model in which two singlet scalar states that only interacts with the Higgs boson is added. Their masses and interaction strengths are fixed by the two requirements of canceling the one-loop…
We present a scalar dark matter (DM) model where DM ($X_I$) is stabilized by a local $Z_2$ symmetry originating from a spontaneously broken local dark $U(1)_X$. Compared with the usual scalar DM with a global $Z_2$ symmetry, the local $Z_2$…
Supersymmetric extensions of the Standard Model have been in vogue for over half a century. They have many interesting theoretical properties like calculability, absence of quadratic divergences, and phenomenologically impactful features…