Related papers: Constraining Multi-scalars models with colliders a…
Following the discovery of a Higgs boson, there has been renewed interest in the general 2-Higgs-Doublet Model (2HDM). A model with One Inert Doublet plus One Higgs Doublet (I(1+1)HDM), where one of the scalar doublets is "inert" (since it…
In this work we explore the possibility of incorporating particle physics motivated scalar fields to the dark matter cosmological model. In this landscape, we consider the classical complex scalar field in a certain region in the parameter…
A central objective of future collider experiments is to probe the structure of the Higgs potential, which requires access to trilinear scalar couplings, in particular the self-coupling of the observed Higgs boson. While this coupling is…
One of the simplest models of dark matter is that where a scalar singlet field S comprises some or all of the dark matter, and interacts with the standard model through an HHSS coupling to the Higgs boson. We update the present limits on…
We find bounds on scalar masses resulting from a criterion of naturalness, in a broad class of two Higgs doublet models (2HDMs). Specifically, we assume the cancellation of quadratic divergences in what are called the type I, type II,…
There could be another scalar in nature quasi-degenerate with the observed one (h125). This is possible in models such as the Next-to-Minimal Supersymmetric Standard Model (NMSSM). The scenario(s) with a single Higgs boson can be compared…
Two-Higgs-doublet models (2HDM) are simple extensions of the Standard Model (SM) where the scalar sector is enlarged by adding a weak doublet. As a result, the Higgs potential depends in general on several free parameters which have to be…
One of the main motivations for low energy supersymmetric theories is their ability to address the hierarchy and naturalness problems in the Higgs sector of the Standard Model. In these theories, at least two doublets of scalar fields are…
The trilinear Higgs coupling $\lambda_{hhh}$ is a crucial tool to probe the structure of the Higgs potential and to search for possible effects of physics beyond the Standard Model (SM). Focusing on the Two-Higgs-Doublet Model as a concrete…
We consider the Higgs sector in an extension of the MSSM with extra SM singlets, involving an extra $U(1)^\prime$ gauge symmetry, in which the domain-wall problem is avoided and the effective $\mu$ parameter is decoupled from the new gauge…
The set of sum rules for a wide class of nonminimal Higgs models has been obtained. Difficulties and ways for revealing the possibilities of studying extended Higgs models at colliders have been revealed with the use of these sum rules and…
Scalar sectors with several Higgs doublets, a CP invariant potential, and a CP violating vacuum, possess a mass spectrum in which, unexpectedly, new scalars cannot have masses much larger than the electroweak scale once perturbativity…
We study phenomenological implications of the ATLAS and CMS hint of a $125\pm 1$ GeV Higgs boson for the singlet, and singlet plus doublet non-supersymmetric dark matter models, and for the phenomenology of the CMSSM. We show that in scalar…
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…
The currently accepted mathematical description of the fundamental constituents and interactions of matter is the Standard Model of particle physics. Its last missing particle, the famous Higgs boson, was observed at the Large Hadron…
We examine some of the theoretical and phenomenological implications of the Higgs boson discovery and discuss what these imply for future Higgs studies at the LHC and future colliders. In particular, one of the outstanding unanswered…
We estimate the bounds on Higgs and sparticle masses and discuss their correlations in the constrained minimal supersymmetric standard model (CMSSM). In our analysis we have applied the present constraints from collider and low energy…
We study constraints on the hidden sector model mediated by an additional SU(2) Higgs doublet from the phenomenology of Higgs bosons. The hidden sector is assumed to contain a hidden U(1) gauge symmetry and the hidden U(1) gauge boson gets…
We study a new physics scenario with two inert and one active scalar doublets, hence a 3-Higgs Doublet Model (3HDM). We impose a $Z_2 \times Z'_2$ symmetry onto such a 3HDM with one inert doublet odd under the $Z_2$ transformation and the…
Classifying the symmetries of the scalar sector in multi-Higgs-doublet models is the main focus of this thesis. We have found certain symmetries that are always broken in models with more than two doublets, which we name "frustrated…