Related papers: Higgs data confronts Sequential Fourth Generation …
Particle physics model building within the context of string theory suggests that further copies of the Higgs boson sector may be expected. Concerns regarding tree-level flavor changing neutral currents are easiest to allay if little or no…
We revisit an extension of the MSSM by adding a hypercharge-neutral, SU(2)-triplet chiral superfield. Similar to the NMSSM, the triplet gives an additional contribution to the quartic coupling in the Higgs potential, and the mass of the…
The latest electroweak precision data are analyzed assuming the existence of the fourth generation of leptons ($N, E$) and quarks ($U, D$), which are not mixed with the known three generations. If all four new particles are heavier than $Z$…
We perform a comprehensive statistical analysis of the standard model (SM) with three and four generations using the latest Higgs search results from LHC and Tevatron, the electroweak precision observables (EWPOs) measured at LEP and SLD…
It is expected that the LHC will soon discover the Higgs boson, or that failure to find it will severely constrain its production cross-section over a large mass range. Either one of these results spells trouble for a fourth generation that…
Recent fits of electroweak precision data to the Standard Model (SM) with a 4th sequential family (SM4) point to a possible "three-prong composite solution": (1) the Higgs mass is at the TeV-scale, (2) the masses of the 4th family quarks…
Some vectorlike quarks are added to the Higgs triplet model with the motivation of fitting the recent Higgs boson data released by LHC and Tevatron collaborations. These vectorlike quarks can suppress the cross section of $gg\to h$ sizably,…
I present comprehensive analyses of the viable parameter regions of the Standard Model of particle physics and two of its extensions: the Standard Model with four fermion generations and the Two-Higgs-Doublets model of type II. Applying…
Models with extended Higgs boson sectors are of prime importance for investigating the mechanism of electroweak symmetry breaking for Higgs decays into four fermions and for Higgs-production in association with a vector bosons. In the…
We consider the two-Higgs-doublet model with explicit CP-violation, where the effective Higgs potential is not CP-invariant at the tree-level. Three neutral Higgs bosons of the model are the mixtures of CP-even and CP-odd bosons which exist…
If next generations of heavy quarks and leptons exist within the standard model (SM), they can manifest themselves in Higgs boson production at the Tevatron and the LHC, before being actually observed. This generation leads to an increase…
The extension of the Higgs sector with an additional complex triplet field is often considered for generating the neutrino mass by the Type-II seesaw mechanism. Such an extension generally predicts $\rho\neq1$, where $\rho$ is the…
We combine results from searches by the CDF and D0 Collaborations for a standard model Higgs boson (H) in the processes gg->H->W+W- and gg->H->ZZ in p-pbar collisions at the Fermilab Tevatron Collider at sqrt(s)=1.96 TeV. With 8.2 fb-1 of…
We present lower bounds on the Higgs boson mass in the Standard Model with three and four fermion generations SM(3,4), as well as upper bounds on the lightest Higgs boson mass in the minimal supersymmetric extension of the SM with three and…
The recent ATLAS and CMS experiments show the first observations of a new particle in the search for the Standard Model Higgs boson at the LHC. We revisit the scenario that high-dimensional operators of fermions must be present due to the…
The existence of the fourth quark-lepton generation is not excluded by the electroweak precision data. However, the recent results on the 126 GeV higgs boson production and decay do not allow an extra generation at least as far as the…
In light of recent experimental results, we present updated bounds on the lightest Higgs boson mass in the Standard Model (SM) and in the Minimal Supersymmetric extension of the Standard Model (MSSM). The vacuum stability lower bound on the…
The production of three Higgs bosons at hadron colliders can be enhanced by a double-resonant effect in the $\mathbb{Z}_2$-symmetric two-real-singlet extension of the Standard Model, making it potentially observable in future LHC runs. The…
Discovering CP-violating effects in the Higgs sector would constitute an indisputable sign of physics beyond the Standard Model. We derive constraints on the CP-violating Higgs-boson couplings to top and bottom quarks as well as to tau…
In composite Higgs models the Higgs boson arises as a pseudo-Goldstone boson from a strongly-interacting sector. Fermion mass generation is possible through partial compositeness accompanied by the appearance of new heavy fermionic…