Related papers: On Testing for New Couplings in Top Quark Decay
A search is presented for three additional operators that would lead to anomalous WW$\gamma$ or WWZ couplings with respect to those in the standard model. They are constrained by studying events with two vector bosons; a W boson decaying to…
The production of top quark pairs in association with a hard gluon in $e^+e^-$ collisions at the NLC provides an opportunity to probe for anomalous $t\bar tg$ couplings, \eg, the chromoelectric and chromomagnetic moments of the top. We…
We propose to utilize angularity distributions in Higgs boson decay to probe light quark Yukawa couplings at $e^+e^-$ colliders. Angularities $\tau_a$ are a class of 2-jet event shapes with variable and tunable sensitivity to the…
We consider the possibility of studying novel particles at the TeV scale with enhanced couplings to the top quark via top quark pair production at the LHC and VLHC. In particular we discuss the case of neutral scalar and vector resonances…
It was reported that the NNLO correction to the total cross section near the ttbar threshold in e+e- collisions is as large as the NLO correction to it. In the thesis, we improve the convergence of the perturbative series of the total cross…
In the context of $SU(2)_L\times U(1)$ dimension six operators we study the potential of the LHeC to provide information on top quark effective interactions. We focus on single antitop production and how it is affected not only by the…
We present a measurement of the ratio of the top-quark branching fractions $R=\mathcal{B}(t\rightarrow Wb)/\mathcal{B}(t\rightarrow $ $q$ represents quarks of flavors $b$, $s$, or $d$, in the final state, in events with two charged leptons,…
A feasibility study of the measurement of the top-Higgs Yukawa coupling at a future linear e+e- collider operating at sqrt(s)=800 GeV is presented. As compared to previous existing studies, much effort has been put in a ``realistic…
Single top quark events produced in the t channel are used to set limits on anomalous Wtb couplings and to search for top quark flavour-changing neutral current (FCNC) interactions. The data taken with the CMS detector at the LHC in…
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…
We present a measurement of the fraction f_+ of right-handed W bosons produced in top quark decays, based on a candidate sample of ttbar events in the l+jets and dilepton decay channels corresponding to an integrated luminosity of 370 pb^-1…
We explored the coupling of strange quark to the state of mass close to 126 GeV recently observed by the ATLAS and CMS experiments at the LHC. An enhanced coupling relative to the expectations for a SM Higgs has the effect of increasing…
Angular distributions of a mu+ and a b-quark resulting from the decay of a top quark produced at the e+e- linear collider with an unpolarized and a 100% longitudinally polarized electron beam are presented. The results of the standard model…
In 0.9 fb$^{-1}$ of $p \bar p$ collisions, D0 has observed an excess of events with an isolated lepton, missing transve rse momentum, and two to four jets. This excess is consistent with single top quark production. We examine these data to…
To properly discover a charged Higgs Boson ($H^\pm$) requires its spin and couplings to be determined. We investigate how to utilize $\ttbar$ spin correlations to analyze the $H^\pm$ couplings in the decay $t\to bH^+\to b\tau^+\nu_\tau$.…
The electroweak production and subsequent decay of single top quarks in the $t$-channel is determined by the properties of the $Wtb$ vertex, which can be described by the complex parameters of an effective Lagrangian. An analysis of a…
We report the combination of recent measurements of the helicity of the W boson from top quark decay by the CDF and D0 collaborations, based on data samples corresponding to integrated luminosities of 2.7 - 5.4 fb^-1 of ppbar collisions…
The measurement of the top quark polarization, sensitive to the electroweak coupling structure, in t-channel single-top production is presented. Events are analyzed corresponding to an integrated luminosity of approximately…
In the presence of an electric dipole coupling of the top quark to a photon, and an analogous "weak" dipole coupling to the Z, CP violation in the process e+e- -> t tbar leads to the polarization of the top and anti-top. This polarization…
We perform a multi-parameter global analysis of all data available till date from the ATLAS, CMS and Tevatron experiments, on the signals of a Higgs boson, to investigate how much scope exists for departure from the standard model…