Related papers: The hierarchy problem and the vacuum stability in …
A vast literature on the theory and phenomenology of Two-Higgs-Doublet models (2HDM) exists since long. However, the present situation demands a revisit of some 2HDM properties. Now that a 125 GeV scalar resonance has been discovered at the…
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…
We show that a neutral scalar field, \sigma, of two Higgs doublet extensions of the Standard Model incorporating the seesaw mechanism for neutrino masses can be identified as a consistent {\it warm} dark matter candidate with a mass of…
In the present work we study the scalar singlet as well as the Two-Higgs Doublet model inert dark matter particles impact on compact objects, and we provide the first constraints of the parameter space using neutron stars. The models…
The present work aims to study an extension of the Standard Model (SM) that addresses the prominent SM shortcomings, i.e., can explain the neutrino mass, the dark matter (DM) content, and the matter-antimatter asymmetry of the Universe. The…
We propose the simplest possible renormalizable extension of the Standard Model - the addition of just one singlet scalar field - as a minimalist model for non-baryonic dark matter. Such a model is characterized by only three parameters in…
One of the simplest extensions of the Standard Model (SM) comprises the inclusion of a massive real scalar field, neutral under the SM gauge groups, to be a dark matter candidate. The addition of a dimension-six term into the potential of…
We study the connection between collider and dark matter phenomenology in the singlet extension of the Georgi-Machacek model. In this framework, the singlet scalar serves as a suitable thermal dark matter (DM) candidate. Our focus lies on…
The hierarchy problem is investigated in the $\mathbb{Z}_2$ Two Higgs Doublet extension of the Standard Model. From the quadratic divergences of the Higgs field propagators fine-tuning constraints are extracted and solved. This leads to the…
Higgs portal models are the most minimal way to explain the relic abundance of the Universe. They add just a singlet that only couples to the Higgs through a single parameter that controls both the dark matter relic abundance and the direct…
Two-Higgs-Doublet-Models (THDMs) are among the simplest extensions of the standard model and are intensively studied in the literature. Using on-shell parameters such as the masses of the additional scalars as input, corresponds often to…
Although theoretically well-motivated as a minimal consistent Dark Matter (DM) model, the Inert Doublet Model (IDM) fell short in explaining the existence of DM in the intermediate mass region ($100-500$ GeV). We try to address this problem…
Multi-component dark matter scenarios constitute natural extensions of standard single-component setups and offer attractive new dynamics that could be adopted to solve various puzzles of dark matter. In this work we present and illustrate…
We promote the idea of multi-component Dark Matter (DM) to explain results from both direct and indirect detection experiments. In these models as contribution of each DM candidate to relic abundance is summed up to meet WMAP/Planck…
We extend the work \cite{Ouazghour:2018mld} to a more general and detailed analysis through studying the naturalness problem and $B$ physics constraints within the context of two higgs doublets model augmented with a complex scalar triplet…
We made global fits of the inert Higgs doublet model (IDM) in the light of collider and dark matter search limits and the requirement for a strongly first-order electroweak phase transition (EWPT). These show that there are still IDM…
We show that, by adding a gauge singlet scalar S to the standard model which is nonminimally coupled to gravity, S can act both as the inflaton and as thermal relic dark matter. We obtain the allowed region of the (m_s, m_h) parameter space…
This work considers an extension of the Standard Model (SM) Higgs sector by a real, scalar singlet field, including applicability to a dark matter (DM) model with the addition of a Yukawa coupling to a Dirac fermion. The collider signatures…
We study the most popular scalar extension of the Standard Model, namely the Two Higgs doublet model, extended by a complex triplet scalar (2HDMcT). Such considering model with a very small vacuum expectation value, provides a solution to…
With a discrete $Z_2$ symmetry being imposed, we introduce a real singlet scalar $S$ to the Higgs triplet model with the motivation of explaining the tentative evidence for a spectral feature at $E_\gamma$ = 130 GeV in the Fermi LAT data.…