Related papers: Determining $V_{tb}$ at Electron-Positron Collider…
To probe the $Wtb$ vertex structure, top-quark and $W$-boson polarisation observables are measured from $t$-channel single-top-quark events produced in proton--proton collisions at a centre-of-mass energy of 8 TeV. The dataset corresponds…
We study in the effective Lagrangian approach the possibility of probing anomalous top quark charged current couplings in the single top production at a high energy e\gamma collider. We analyzed all possible dimension-six CP-conserving…
The Wtb vertex can be probed on future colliders in the processes of single top production (LHC, pp mode, NLC, $\gamma e$ mode) and of top pair production (NLC, e^+ e^- mode). We analyse observables sensitive to anomalous Wtb couplings in…
Top quark production in the process $e^+e^- \rightarrow t\bar{t}$ at a future linear electron positron collider with polarized beams is a powerful tool to determine the scale of new physics. Studies at the $\ttbar$ threshold will allow for…
A measurement of the cross section for the production of top quark-antiquark pairs (t tbar) in association with a vector boson V (W or Z) in proton-proton collisions at sqrt(s) = 8 TeV is presented. The results are based on a dataset…
In terms of an effective Lagrangian we investigate the possibilities of probing anomalous top quark couplings, $t \bar{t} H$, $\gamma t \bar{t}$, $Z t \bar{t}$ and $tWb$ at the future linear colliders. It is found that probing anomalous top…
The cross section for the reaction $e^+e^- \to t\bar{t} H$ depends sensitively on the top quark Yukwawa coupling $\lambda_t$. We calculate the rate for $t\bar{t}H$ production, followed by the decay $H\to b\bar{b}$, for a Standard Model…
We present a measurement of the top quark pair ($t\bar{t}$) production cross section ($\sigma_{t\bar{t}}$) in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV using 230 pb$^{-1}$ of data collected by the D0 experiment at the Fermilab Tevatron…
A search is presented for single production of a vector-like $B$ quark decaying into a Standard Model $b$-quark and a Standard Model Higgs boson, which decays into a $b\bar{b}$ pair. The search is carried out in 139 fb$^{-1}$ of $\sqrt{s} =…
An influence of the anomalous Wtb coupling on forward-backward asymmetry of top quark pair production at the Tevatron is investigated taking into account decays of the top quarks to 6 fermion final states containing one charged lepton. To…
In the standard model, for the t --> W b decay mode, the relative phase is 0-degrees between the dominant A(0,-1/2) and A(-1, -1/2) helicity amplitudes. However, in the case of an additional large t_R --> b_L chiral weak-transition moment,…
The top quark sector is almost decoupled from lighter quark generations due to the fact that $V_{tb}\approx$~1. The current experimental measurements of $V_{tb}$ are compatible with the Standard Model expectations but are still dominated by…
We study the sensitivity of the Large Hadron Collider (LHC) to top quark chromomagnetic (CMDM) and chromoelectric (CEDM) dipole moments and $Wtb$ effective couplings in single-top production in association with a $W^-$ boson, followed by…
The quartic gauge coupling (QGC) of the electroweak interaction can be used as a probe for physics beyond the Standard Model and has been previously measured at the Large Hadron Collider. However, to achieve sensitivity to small deviations…
Recently it was shown that, in the framework of superstring inspired $\E$ models, the presence of generation dependent discrete symmetries allows us to construct a phenomenologically viable class of models in which the three generations of…
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…
Precise measurements of the properties of the top quark test the Standard Model (SM) and can be used to constrain new physics models. The top quark pair charge asymmetry is an asymmetry predicted to occur beyond leading-order QCD in the SM,…
We parameterize the non-universal couplings of t-t-Z and t-b-W in the electroweak chiral lagrangian approach, and examine the constraints on these parameters from the LEP data. We also study how the SLC, Tevatron, LHC and NLC can improve…
A combination of the searches for pair-produced vector-like partners of the top and bottom quarks in various decay channels ($T$$\rightarrow$$Zt/Wb/Ht$, $B$$\rightarrow$$Zb/Wt/Hb$) is performed using 36.1 fb$^{-1}$ of $pp$ collision data at…
The electroweak symmetry breaking (EWSB) mechanism is still an undecided question in particle physics. We propose to utilize the single top quark and Higgs associated production ($th$), $Zh$ production via gluon fusion at the LHC to probe…