Related papers: Vector Leptons in the Higgs Triplet Model
We replace the scalar Higgs doublet with a vector Higgs boson doublet to the unified electroweak W-S model and find most of important features of W-S model are kept unchanged only the Higgs boson now become vector bosons. Lorentz invariance…
The stability of the Standard Model (SM) Higgs vacuum is a long-standing issue in particle physics. The SM Higgs quartic coupling parameter is expected to become negative at high scales, potentially generating an unstable vacuum well before…
Higgs triplet fields are introduced various new physics models such as the type-II seesaw model, the left-right symmetric model and so on. The vertex of a charged Higgs boson and weak gauge bosons, $H^\pm W^\mp Z$, appears at the tree level…
In extended Higgs models, a discrete symmetry is needed in the quark sector to avoid tree-level flavor-changing neutral currents. However, this is not necessary the case in the lepton sector. We consider a model in which one Higgs couples…
We study the Higgs boson decays $h \to Z\gamma$ and $h \to m_VZ$ in a model with vectorlike fermions and $U(1)_X$ symmetry ($U(1)_X$VLFM), where $m_V$ is a vector meson ($\rho,\ \omega,\ \phi,\ J/\psi,\ \Upsilon$). The exotic Yukawa…
In models where an additional SU(2)-doublet that does not have couplings to fermions participates in electroweak symmetry breaking, the properties of the Higgs boson are changed. At tree level, in the neighborhood of the SM-like range of…
The newly discovered resonance at 125 GeV has properties consistent with the Standard Model (SM) Higgs particle, although some production and/or decay channels currently exhibit O(1) deviations. We consider scenarios with a new scalar…
We show that inclusion of a single generation of vector-like leptons in the Two-Higgs Doublet Models significantly enlarges the allowed parameter space consistent with the muon anomalous magnetic moment, as well as with other theoretical…
We look for minimal extensions of Standard Model with vector like fermions leading to precision unification of gauge couplings. Constraints from proton decay, Higgs stability and perturbativity are considered. The simplest models contain…
We investigate the production of vector-like quarks with charge $5/3$ at the LHC and their subsequent decays into new singly or doubly charged bosons plus a heavy quark (top or bottom). In particular, we explore final states with same-sign…
We study a minimal extension to the Standard Model with an additional real scalar triplet, $\Sigma$, and a single vector-like quark, $T$. This class of models appear naturally in extensions of the Littlest Higgs model that incorporate dark…
We consider a simple extension of the Standard Model (SM) with a vector-like lepton and a local $U(1)'$ symmetry, motivated by the recent experimental anomalies in the muon $g-2$ and the $W$ boson mass. The $U(1)'$ symmetry is spontaneously…
In the lepton-specific version of two Higgs doublet models, a discrete symmetry is used to couple one Higgs, $\Phi_2$, to quarks and the other, $\Phi_1$, to leptons. The symmetry eliminates tree level flavor changing neutral currents…
We discuss novel effects in the phenomenology of a light Higgs boson within the context of composite models. We show that large modifications may arise in the decay of a composite Nambu-Goldstone boson Higgs to a photon and a Z boson, h ->…
The lightest Higgs scalar boson mass in supersymmetry can be raised significantly by extra vector-like quark and lepton supermultiplets with large Yukawa couplings but dominantly electroweak-singlet masses. I consider models of this type…
An extension of the left--right symmetric model has been constructed which gives in a natural way the three lepton decay modes of the proton which have been suggested as an explanation for the atmospheric neutrino anomaly. We write down the…
We consider the scenario where the composite Higgs arising as a pNGB in a two-site model with a non-local term included. Constraints from pion scattering and electroweak precision test are considered. We discuss the effects of composite…
We study the effects of extended fermion sectors, respecting custodial symmetry, on Higgs production and decay. The resulting protection for the Z->b_L b_L and Z->\tau_R\tau_R decays allows for potentially interesting signals in Higgs…
We study Higgs boson pair production processes at future hadron and lepton colliders including the photon collision option in several new physics models; i.e., the two-Higgs-doublet model, the scalar leptoquark model, the sequential fourth…
We study the Georgi-Machacek two triplet, one doublet model in the context of LEP2, and show that cascade decays of Higgs bosons to lighter Higgs bosons and a virtual vector boson may play a major role. Such decays would allow the Higgs…