Related papers: Higgs Triplets, Decoupling, and Precision Measurem…
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)…
We study a two Higgs doublet model extended by a complex singlet scalar, in which the imaginary part of the singlet serves as a dark matter (DM) candidate. In this model, degenerate masses of the three neutral Higgs bosons are crucial for…
The Standard Model (SM) with a light Higgs boson provides a very good description of the precision electroweak observable data coming from the LEP, SLD and Tevatron experiments. Most of the observables, with the notable exception of the…
After the discovery of a Higgs boson at the LHC, the next important step is to measure its couplings to fermions and bosons to unravel its true nature. In order to ultimately test the shape of the scalar potential that triggers the…
We discuss an extension of the minimal Higgs triplet model with a classically conformal invariance and with a gauged $U(1)_{B-L}$ symmetry. In our scenario, tiny masses of neutrinos are generated by a hybrid contribution from the type-I and…
Electroweak precision observables are fundamentally important for testing the standard model (SM) or its extensions. The influences to observables from new physics within the electroweak sector can be expressed in terms of oblique…
It is widely believed that existing electroweak data requires a Standard Model Higgs to be light while electroweak and flavour physics constraints require other scalars charged under the Standard Model gauge couplings to be heavy. We…
A discrete symmetry between quarks and (generalized) leptons can exist in nature, and its spontaneous symmetry breaking scale can be as low as a few TeV. Such a discrete symmetry also has interesting implications for how electroweak…
The proper renormalization of mixing angles in quantum field theories is a long-standing problem. It is relevant for the renormalization of the quark mixing matrix in the Standard Model and for various mixing scenarios in theories beyond.…
The scalar sector of the Standard Model is extended to include an arbitrary assortment of scalars. In the case where this assignment does not preserve $\rho=1$ at the tree-level, the departure from unity itself puts the most stringent…
We construct supersymmetric theories in which the correct scale for electroweak symmetry breaking is obtained without significant fine-tuning. We calculate the fine-tuning parameter for these theories to be at the 20% level, which is…
The simplest extension of the Standard Model by only one real singlet scalar can explain the observed dark matter relic density while giving simultaneously a strongly first-order electroweak phase transition in the early universe. However,…
We investigate the correlation between a possible deviation in the discovered Higgs boson $h(125)$ couplings from the Standard Model prediction and the mass scale ($M_{\text{2nd}}$) of the next-to-lightest Higgs boson in models with…
Many beyond the Standard Model (BSM) scenarios involve Higgs couplings to additional electroweak fields. It is well established that these new fields may modify Higgs gamma-gamma and gamma-Z decays at one-loop. However, one unexplored…
In a number of Higgs-portal models, an $SU(2)$ isospin-singlet scalar boson generically appears at the electroweak scale and can mix with the Standard Model (SM) Higgs boson with a mixing angle $\alpha$. This singlet scalar boson can have…
A definition of the rho parameter based on the Higgs couplings with the gauge bosons, rho_h= g_{hWW}}/c^2_W g_{hZZ}, is proposed as a new probe into the origin of the mechanism of electroweak symmetry breaking. While $\rho_h=1$ holds in the…
In this paper we assume the Higgs is an elementary scalar, and study how new physics could affect its couplings to electroweak gauge bosons. Adding LHC data to LEP data provides new, more stringent limits, particularly when the Higgs to two…
Models of Gauge-Higgs unification in extra dimensions offer a very elegant playground where one can study electroweak symmetry breaking. The nicest feature is that gauge symmetry itself protects the Higgs potential from divergences, thus…
New particles entering into self-energies of the Higgs boson would necessarily modify loop-induced couplings of the Higgs, if the new particle carries standard model gauge quantum numbers. For a 1 TeV new particle, deviations in these…
We study tree level corrections to precision electroweak physics in the recently proposed Higgsless models in warped space. Such models inherit from their similarity with technicolor theories a large contribution to the oblique parameters,…