Related papers: Single Vectorlike Quark Production at the LHC
Vector-like quarks (VLQ) that couple preferentially to third-generation Standard Model (SM) quarks are a well-motivated extension of the SM, which could solve in particular the hierarchy problem. While VLQs can be produced in pairs via the…
We review the most popular models proposed to explain the anomalous forward-backward asymmetry in t tbar production at the Tevatron. We discuss their viability in view of recent LHC data. We summarise their predictions for charge…
The top quark forward-backward asymmetry measured at the Fermilab Tevatron collider deviates from the standard model prediction. A W^prime boson model is described, where the coupling W^prime-t-d is fixed by the tt_bar forward-backward…
A simple variant of a realistic flavour symmetry scheme for fermion masses and mixings provides a possible interpretation of the diphoton anomaly as an electroweak singlet "flavon". The existence of TeV scale vector-like T-quarks required…
A high energy muon collider can provide new and complementary discovery potential to the LHC or future hadron colliders. Leptoquarks are a motivated class of exotic new physics models, with distinct production channels at hadron and lepton…
We investigate the production of heavy coloured scalars and vectors and their relevance at LHC for the study of vector-like quarks ($T$). These coloured states ($C$) are present in a large number of extensions of the standard model, in…
A colored weak singlet scalar state with hypercharge 4/3 is one of the possible candidates for the explanation of the unexpectedly large forward-backward asymmetry in $t \bar t$ production as measured by the CDF and D0 experiments. We…
A search for pair-produced heavy vector-like charge-2/3 quarks, T, in pp collisions at a center-of-mass energy of 7 TeV, is performed with the CMS detector at the LHC. Events consistent with the flavor-changing-neutral-current decay of a T…
The possibility of a vectorlike top partner decaying to a new colourless weak-singlet scalar or pseudoscalar has attracted some attention in the literature. We investigate the production of a weak-singlet charge-$2/3$ $T$ quark that can…
The dimuon and dielectron data from the Tevatron $\bar pp$ collider are used to probe for heavy quarks, which decay dominantly via flavour changing neutral current. Depending on whether the $FCNC$ decay occurs at the tree or loop level, one…
Single top-quark production, via weak-interaction processes, is an important test of the standard model, potentially sensitive to new physics. However, this measurement is much more challenging at the Tevatron than originally expected. We…
We consider the top quark charge asymmetry in the process $pp \to t\bar{t}+\gamma$ at the 13 TeV LHC. The genuine tree level asymmetry in the $q\bar{q}$ channel is large with about -12%. However, the symmetric $gg$ channel, photon radiation…
Single-top-quark production probes the charged-current weak interaction of the top quark, and provides a direct measurement of the CKM matrix element V_{tb}. We perform two independent analyses to quantify the accuracy with which the…
Associated single top production with a Z boson or a photon at large hadron colliders provides a precise determination of top flavour-changing neutral couplings. The best way to measure these couplings with the up quark at Tevatron is to…
A precise measurement of the top quark mass, a fundamental parameter of the Standard Model, is among the most important goals of top quark studies at the Large Hadron Collider. Apart from the standard methods, numerous new observables and…
This work provides an overview on the current status of phenomenology and searches for heavy vector-like quarks, which are predicted in many models of new physics beyond the Standard Model. Searches at Tevatron and at the LHC, here listed…
We use top quark pair production as a probe of top-philic non-resonant new physics. Following a low energy effective field theory approach, we calculate several key observables in top quark pair production at hadron colliders (e.g., total…
The Large Hadron Collider(LHC) has completed its run at 8 TeV with the experiments ATLAS and CMS having collected about 25 $\rm fb^{-1}$ of data each. Discovery of a light Higgs boson, coupled with lack of evidence for supersymmetry at the…
A comprehensive extension of the ordinary 2-Higgs Doublet Model (2HDM), supplemented by Vector-Like Quarks (VLQs), in the "alignment limit" is presented. In such a scenario, we study the possibility that Large Hadron Collider (LHC) searches…
Both CDF and DO report a forward-backward asymmetry in t-tbar production that is above the standard model prediction. We review new physics models that can give a large forward backward asymmetry in t-tbar production at the Tevatron and the…