Related papers: Vector-like quarks: status and new directions at t…
Searches for new low-mass matter and mediator particles have actively been pursued at fixed target experiments and at $e^+e^-$ colliders. It is challenging at the CERN LHC, but they have been searched for in Higgs boson decays and in $B$…
We explore the effects induced by a finite width in processes of pair production of a heavy top-quark partner and its subsequent decay into a bosonic Dark Matter (DM) candidate -- either scalar or vector -- and a SM up-type quark at the…
Vector-like leptons (VLLs) as one kind of interesting new particles can produce rich phenomenology at low- and high-energy experiments. In the framework of the singlet vector-like leptons with scalar (VLS) model, we investigate the…
Following up on our earlier study in [J. Bardhan et al., Machine learning-enhanced search for a vectorlike singlet B quark decaying to a singlet scalar or pseudoscalar, Phys. Rev. D 107 (2023) 115001; arXiv:2212.02442], we investigate the…
We study the pair production of scalar top-quark partners decaying to a top-quark pair plus large missing energy at the LHC, a signature which appears in numerous models that address outstanding problems at the TeV-scale. The severe…
At the LHC, a TeV-scale leptoquark (LQ) that decays dominantly to a top quark ($t$) and a light charged lepton ($\ell=e,\mu$) would form a resonance system of \emph{boosted-$t$ $+$ high-$p_{\rm T}$-$\ell$}. We consider all possible vector…
Recently, the vector-like leptons (VLLs) as a simple extension to the standard model (SM) have attracted widespread attention both in theory and experiments. The present collider searches mainly focus on the studies of their prompt decays,…
In this work, we continue our exploration of TeV-scale vector-like fermion signatures inspired by a Grand Unification scenario based on the trinification gauge group. A particular focus is given to pair-production topologies of vector-like…
The results of a previous search by the CMS Collaboration for squarks and gluinos are reinterpreted to constrain models of leptoquark (LQ) production. The search considers jets in association with a transverse momentum imbalance, using the…
This paper describes a search for the single production of an up-type vector-like quark ($T$) decaying as $T \rightarrow Ht$ or $T \rightarrow Zt$. The search utilises a dataset of $pp$ collisions at $\sqrt{s}=13$ TeV collected with the…
Weak decays of the vector $D^{*0}$ and $B_{(s)}^{*0}$ mesons to the $\mumu$ final state provide novel potential to test the Standard Model of particle physics. Such processes have extremely small branching fractions as the vector mesons are…
Though some LHC searches for new physics exceed the TeV scale, there may be discoveries waiting to be made at much lower masses. We outline a simple quirk model, motivated by models that address the hierarchy problem through neutral…
We analyze decays of vectorlike quarks in extensions of the standard model and a two Higgs doublet model. We identify several typical patterns of branching ratios of the lightest new up-type quark, $t_4$, and down-type quark, $b_4$,…
Models with new vector-like quarks can produce observable quark mixing effects which are forbidden in the Standard Model. We classify all such models and write down the effective Lagrangian that results from integrating out the new quarks.…
In this paper, we explore the signature of a simplified model which includes a new singlet scalar state and a vector like quark at future lepton colliders. In particular, we study the production of the new singlet scalar in association with…
The current situation for vector meson spectroscopy is outlined, and it is shown that the data are inconsistent with the generally-accepted model for meson decay. A possible resolution in terms of exotic mesons is given. Although this…
We examine the prospects for LHC discovery of SU(2)_L singlet vector-like quarks that obey Minimal Flavour Violation (MFV) and are consistent with lower energy phenomenology. We study models where the vector-like quarks have the same…
Rare $B$-meson decays, suppressed in the Standard Model (SM) by the GIM mechanism, are sensitive probes of new physics. In particular, loop-level $b \to s$ transitions can reveal effects of heavy virtual particles such as vector-like quarks…
We report on a search for vector-like quarks and leptoquarks at D0. In the absence of any significant excess over the expectations, we present the most stringent limits to date.
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…