Related papers: Vector-like Quarks
We review the theory and phenomenology of isosinglet vector-like quarks (VLQs). In recent years, interest in VLQs has been increasing, due to their contributions to new physics effects that can be tested in experiments at LHC and…
The Standard Model of particle physics explains many natural phenomena yet remains incomplete. Vectorlike quarks and leptoquarks lie at the heart of many extensions to the Standard Model seeking to address the hierarchy problem, or the…
There are strong arguments favoring the Flavor Democracy hypothesis (or the Democratic Mass Matrix approach) within the Standard Model framework. However, the large mass of the top quark ($m_t >> m_b, m_\tau$) poses an obstacle to the…
Experimental searches for vector-like quarks have until now only considered their decays into Standard Model particles. However, various new physics scenarios predict additional scalars, so that these vector-like quarks can decay to new…
We study the patterns of flavour violation in renormalisable extensions of the Standard Model (SM) that contain vector-like quarks (VLQs) in a single complex representation of either the SM gauge group $G_{SM}$ or $G_{SM}' = G_{SM} \times…
Vector-like quarks (VLQs) are attractive extensions to the Standard Model. They mix with the SM quarks and can lead to rich phenomenology. Determination of VLQ's interaction structure with the SM is then an important issue, which can be…
We show how a novel fine-tuning problem present in the Standard Model can be solved through the introduction of a single flavour symmetry G, together with three $Q = - 1/3$ quarks, three $Q = 2/3$ quarks, as well as a complex singlet…
Vector-like Quarks (VLQs) are potential signatures of physics beyond the Standard Model at the TeV energy scale and major efforts have been put forward at both ATLAS and CMS experiments in search of these particles. In order to make these…
We study, in a systematic way, the $V_{\text{CKM}}$ unitarity relations which arise in extensions of the three generations Standard Model (3gSM) involving the addition of vector-like quarks (VLQ). In particular, we emphasize the effect of…
The Nelson-Barr mechanism to solve the strong CP problem requires vector-like quarks (VLQs) to transmit the spontaneous CP breaking to the SM. We study the scenario where only these VLQs are within reach at the TeV scale while the…
This work analyses a class of extensions of the Standard Model through the lens of a novel exact parameterisation. This parameterisation is specially suitable to the analysis of extensions of the Standard Model with non-unitary mixing…
The standard model extended with the pairs of the vector-like families is studied. The model independent analysis for an arbitrary case and an explicit realization for the case with one pair of the heavy vector-like families are considered.…
We explain why vector-like fermions are natural candidates to lift the Standard Model vacuum instability. Results are further discussed from the viewpoint of criticality. Several models allow for vector-like quarks and leptons in the…
Several theories beyond the Standard Model (BSM) predict heavy neutral leptons, or long-lived particles with unique signatures which are difficult to reconstruct. Another area of interest are vector-like quarks which lie at the heart of…
In this paper, we tension the scope of the $q\bar q, gg\to T \bar T$ production process against that of the same-charge $uu\to TT$ one in searching for Vector-Like Quarks (VLQs) with electromagnetic charge $+2/3$ at the Large Hadron…
We emphasise that even in the extreme chiral limit where only the top and bottom quarks acquire mass, quark mixing is physically meaningful. This implies that the natural value of $|V_{13}|^2 + |V_{23}|^2$ is of order one, which is to be…
Vector-Like Quarks (VLQs) are predicted by several theoretical scenarios of new physics and, having colour quantum numbers, can copiously be produced at the Large Hadron Collider (LHC), so long that their mass is in the testable kinematic…
A vector-like extension of the standard model for heavier quarks and leptons with $SU(2)\times U(1)$ gauge symmetry and only one Higgs doublet is examined. This scheme incorporates infinitely many fermions and avoids the appearance of a…
We present VLQBounds, a public, data-driven Python framework for testing Vector-Like Quark (VLQ) scenarios against Large Hadron Collider (LHC) exclusion limits from ATLAS and CMS. The framework incorporates public results on both pair and…
The extension of the standard model with pairs of the vector-like families is studied. The quark mixing matrices for the left- and right-handed charged currents, as well as those for the flavour changing neutral currents, the Z and Higgs…