Related papers: Vector-like quarks with a scalar triplet
If the gauge fields of the Standard Model propagate in TeV-size extra dimensions, they rapidly become strongly coupled and can form scalar bound states of quarks and leptons. If the quarks and leptons of the third generation propagate in 6…
The inert doublet model (IDM), a minimal extension of the Standard Model (SM), provides a scalar dark matter (DM) candidate that belongs to the additional Higgs doublet. The model faces challenges in achieving the correct relic abundance…
We investigate the implications of models that achieve a Standard Model-like Higgs boson of mass near 125 GeV by introducing additional TeV-scale supermultiplets in the vector-like 10+\bar{10} representation of SU(5), within the context of…
The little Higgs models typically contain a new vector-like top quark $T$, which plays a key role in breaking the electroweak symmetry. In the context of the littlest Higgs (LH) model, we study single production of this kind of new particle…
Little Higgs models offer a new way to address the hierarchy problem, and give rise to a weakly-coupled Higgs sector. These theories predict the existence of new states which are necessary to cancel the quadratic divergences of the Standard…
We investigate the predictions of a simple extension of the Standard Model where the Higgs sector is composed of one $SU(2)_L$ doublet and one real triplet. We discuss the general features of the model, including its vacuum structure,…
In extensions of two Higgs doublet models with vectorlike quarks, the decays of vectorlike quarks may be easily dominated by cascade decays through charged or neutral Higgs bosons leading to signatures with 6 top or bottom quarks. Since top…
In the framework of strongly interacting dynamics for electroweak symmetry breaking, heavy composite particles may arise and cause observable effects, as they should couple strongly to the resulting Higgs boson and affect the signals that…
With a discrete $Z_2$ symmetry being imposed, we introduce a real singlet scalar $S$ to the Higgs triplet model with the motivation of explaining the tentative evidence for a spectral feature at $E_\gamma$ = 130 GeV in the Fermi LAT data.…
We present a model wherein the Higgs mass is protected from the quadratic one-loop top quark corrections by scalar particles that are complete singlets under the Standard Model (SM) gauge group. While bearing some similarity to Folded…
Vectorlike fermions are an important target for hadron collider searches. We show that the vectorlike quarks may predominantly decay via higher-dimensional operators into a quark plus a couple of other Standard Model fermions. Pair…
Supersymmetry is one of the best motivated possibilities for new physics at the TeV scale. However, both concrete string constructions and phenomenological considerations suggest the possibility that the physics at the TeV scale could be…
A search for singly produced vector-like quarks $Q$, where $Q$ can be either a $T$ quark with charge $+2/3$ or a $Y$ quark with charge $-4/3$, is performed in proton-proton collision data at a centre-of-mass energy of 13 TeV corresponding…
We study discovery prospects for a real triplet extension of the Standard Model scalar sector at the Large Hadron Collider (LHC) and a possible future 100 TeV $pp$ collider. We focus on the scenario in which the neutral triplet scalar is…
We consider the quark sector of theories containing three scalar SU(2)_L doublets in the triplet representation of A4 (or of S4) and three generations of quarks in arbitrary A4 (or S4) representations. We show that, for all possible choices…
We search for an extension of the Standard Model that contains a viable dark matter candidate and that can be embedded into a fundamental, asymptotically safe, quantum field theory with quantum gravity. Demanding asymptotic safety leads to…
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…
Measuring the Higgs couplings accurately at colliders is one of the best routes for finding physics Beyond the Standard Model (BSM). If the measured couplings deviate from the SM predictions, then this would give rise to energy-growing…
In extensions of two Higgs doublet models with vectorlike quarks and leptons the decays of new scalars or fermions can be altered by the presence of the other, depending on the hierarchy of new physics. If new fermions are heavier than…
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…