Related papers: The electroweak fit and constraints on new physics
I review constraints on the Standard Model (SM) Higgs boson from high energy electroweak (EW) precision data. The same data set also strongly limits various mixing effects of hypothetical extra neutral gauge bosons (Z') with the ordinary Z.…
In general electroweak models with weakly coupled (and otherwise arbitrary) Higgs sector there always exists in the spectrum a scalar state with mass controlled by the electroweak scale. A new and simple recipe to compute an analytical…
The main purpose of this thesis is to discuss the impact of electroweak precision measurements on the present knowledge of particle physics, both in the framework of the Standard Model and of its most straightforward extensions. In Chapter…
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…
The Next-to-Minimal Supersymmetric Standard Model (NMSSM) offers a rich framework embedding physics beyond the Standard Model as well as consistent interpretations of the results about the Higgs signal detected at the LHC. We investigate…
We present a novel class of theories where supersymmetry is only preserved in a partial (non-isolated) sector. The supersymmetric sector consists of CFT bound-states that can coexist with fundamental states which do not respect…
Severe constraints on parameters of the minimal supersymmetric standard model follow from a dynamical electroweak symmetry breaking mechanism dominated by top and stop loops. In particular, the lightest Higgs boson mass is expected to be…
Precise measurements of SM particles properties at the LHC allows to look for heavy New Physics in the context of an Effective Field Theory (EFT). These searches, however, often rely on kinematic regions where the validity of the EFT may be…
Based on the framework of Standard Model Effective Field Theory, we performed a few global fits, each containing a subset of dimension-6 operators, for the measurements that are expected at future colliders. The fit for the Higgs and…
Models in which the Higgs boson is a composite pseudo-Nambu-Goldstone boson offer attractive solutions to the Higgs mass naturalness problem. We consider three such models based on the minimal $SO(5) \rightarrow SO(4)$ symmetry breaking…
We present an updated and extended global analysis of the Constrained MSSM (CMSSM) taking into account new limits on supersymmetry from ~5/fb data sets at the LHC. In particular, in the case of the razor limit obtained by the CMS…
In the Minimal Supersymmetric Standard Model (the MSSM), the electroweak symmetry is restored as supersymmetry-breaking terms are turned off. We describe a generic extension of the MSSM where the electroweak symmetry is broken in the…
A Higgs-like particle with a mass of about 126 GeV has been discovered at the LHC. Within the experimental uncertainties, the measured properties of this new state are compatible with those of the Higgs boson in the Standard Model (SM).…
Electroweak precision observables, being highly sensitive to loop contributions of new physics, provide a powerful tool to test the theory and to discriminate between different models of the underlying physics. In that context, the $W$…
In this paper we express the effect of new physics on gauge boson self energy corrections through non-renormalizable dimension six operators. Using the precision electroweak data we then determine a lower bound on the scale ${\l}$…
We propose a solution to the recent $W$ mass measurement by embedding the Standard Model within $E_6$ models. The presence of a new $U(1)$ group shifts the $W$ boson mass at the tree level and introduces a new gauge boson $Z^{\prime}$ which…
We perform a phenomenological fit to all ATLAS, CMS, CDF and D0 Higgs boson data available after Moriond 2012. We allow all Higgs boson branching fractions, its couplings to standard model particles, as well as to an hypothetical invisible…
Our picture of the electroweak interactions continues to improve, with ever more precise constraints on the masses of the Higgs boson(s) and on non-standard physics. Some recent developments include: (a) a calculation of higher-order…
We update the constraints on two-Higgs-doublet models (2HDMs) focusing on the parameter space relevant to explain the present muon $g$$-$$2$ anomaly, $\Delta a_{\mu}$, in four different types of models, type I, II, "lepton specific" (or X)…
Depending on the Higgs-boson and top-quark masses, $M_H$ and $M_t$, the effective potential of the {\bf Standard Model} can develop a non-standard minimum for values of the field much larger than the weak scale. In those cases the standard…