Related papers: Dark Matter in Classically Scale-Invariant Two Sin…
We investigate the collider phenomenology of the standard Hierarchical VEVs Model by proposing a new version, which avoids large flavor changing neutral current interactions, thus, rendering the scale of new physics as low as the…
Theory with $SU(2)\times U(1)$ gauge invariant electroweak Lagrangian describing standard interaction of massless quark doublet without elementary scalar Higgs sector is considered. We show in the main order of $1/N_c$ expansion, that there…
The confirmation of the Higgs boson in Run I data at the Large Hadron Collider (LHC) and the excesses in recent Run II data suggest scenarios beyond the Standard Model (SM). We pursue a study in a minimal model which is an extension of a…
We study two types of models involving a scalar dark matter multiplet of global $O(N)$ symmetry. These models are distinguished by the absence (Type I) or presence (Type II) of a scalar mediator with $Z_{2}$ symmetry. We derive the allowed…
Recent LHC results suggest a standard model (SM)-like Higgs boson in the vicinity of 125 GeV with no clear indications yet of physics beyond the SM. At the same time, the SM is incomplete, since additional dynamics are required to…
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…
We study how collider data and electroweak precision observables affect the parameter space of models including a new dark force mediated by a massive U(1) gauge boson. It acquires mass via a Higgs mechanism in the dark sector which is…
We consider the possibility of an oscillating scalar field accounting for dark matter and dynamically controlling the spontaneous breaking of the electroweak symmetry through a Higgs-portal coupling. This requires a late decay of the…
Recently, the CMS Collaboration observed the hint of a resonance decaying to two photons at about 96 GeV with a local significance of $2.8\sigma$. While it is too early to say whether this will stand the test of time, such a resonance can…
We show that dark matter abundance and the inflationary scale $H$ could be intimately related. Standard Model extensions with Higgs mediated couplings to new physics typically contain extra scalars displaced from vacuum during inflation. If…
We investigate direct detection rates for Dark Matter candidates arise in a $SU(2)_L\times U(1)_Y$ with an additional doublet Higgs proposed by Barbieri, Hall and Rychkov. We refer this model as `Heavy Higgs Model'. The Standard Model Higgs…
In this research we consider a $U(1)_X$ gauge boson acting as a dark matter candidate. The vector dark matter (DM) gets mass when a complex singlet scalar breaks the gauge symmetry spontaneously, adding a second Higgs boson to the spectra.…
We propose a novel mechanism of electroweak symmetry breaking in supersymmetric models, as the one recently discussed by Birkedal, Chacko and Gaillard, in which the Standard Model Higgs doublet is a pseudo-Goldstone boson of some global…
We study the standard model (SM) in its full perturbative validity range between $\Lambda_QCD$ and the $U(1)_Y$ Landau pole, assuming that a yet unknown gravitational theory in the UV does not introduce additional particle thresholds, as…
The inert doublet model (IDM) is a minimal extension of the Standard Model (SM) that can account for the dark matter in the universe. Naturalness arguments motivate us to study whether the model can be embedded into a theory with…
We consider the collider phenomenology of a singlet Majoron model with softly broken lepton number. Lepton number is spontaneously broken when the real part of a new singlet scalar develops vacuum expectation value. With the additional soft…
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 construct a little Higgs model with the most minimal extension of the standard model gauge group by an extra U(1) gauge symmetry. For specific charge assignments of scalars, an approximate U(3) global symmetry appears in the…
We show that the present dark matter abundance can be accounted for by an oscillating scalar field that acquires both mass and a non-zero expectation value from interactions with the Higgs field. The dark matter scalar field can be…
This study is inspired by a scenario, in which the Standard Model, enhanced by an additional dark matter scalar, could be extended up to the Planck scale, while accommodating the low measured value of the Higgs mass. To that end, we study a…