Related papers: Improving $t \bar{t}$ reconstruction in the dilept…
Recent results from the ATLAS and the CMS experiments at the Large Hadron Collider indicate the presence of a top-quark pair bound state near the threshold region. We present a way to reconstruct a toponium state at the $t\bar{t}$ threshold…
A new method to reconstruct charged fragment four-momentum vectors from measured trajectories behind an open, large gap, magnetic dispersion element (a sweeper magnet) has been developed. In addition to the position and angle behind the…
We design a search strategy for the Standard Model $t\bar t t \bar t$ production at the LHC in the same-sign dilepton and trilepton channels. We study different signal features and, given the small expected number of signal events, we…
Top-quark physics is one of the main fields of investigation at the Tevatron accelerator and, ultimately, at the LHC. We perform a phenomenological analysis of ttbar events at hadron colliders, with a focus on observables relying on…
A search for a high mass ttbar resonance in pp collisions at sqrt(s) = 7 TeV at the LHC is presented. We search for such a resonance using the final state where the $W$ bosons from the top quark decay into either an electron or a muon…
We present an approach to predict exclusive $W^+bW^-\bar{b}$ production at lepton colliders that correctly describes the top-anti-top threshold as well as the continuum region. We incorporate $t\bar{t}$ form factors for the NLL threshold…
We report the study of top-quark reconstruction in $e^+e^- \to t\bar{t}$ events at a 500 GeV linear collider using the LCD Fast Simulator. The final states of 6 jets as well as 4 jets and lepton are used. In order to reconstruct the jets,…
We present the first model-independent measurement of the helicity of $W$ bosons produced in top quark decays, based on a 1 fb$^{-1}$ sample of candidate $t\bar{t}$ events in the dilepton and lepton plus jets channels collected by the D0…
We present a measurement of $W$ boson polarization in top-quark decays in $t\bar{t}$ events with decays to dilepton final states using $5.1 {\rm fb^{-1}}$ of integrated luminosity in $p\bar{p}$ collisions collected by the CDF II detector at…
We update present bounds on the helicity of the neutrinos produced in muon decay, including e+ e- -> fbar f LEP 2 data. These significantly reduce the limits derived from all the other electroweak precision data. In Standard Model…
Neutrinos play a crucial role in particle physics, but cannot be tracked in collider experiments. If more than one neutrino is present in a collision event, it is impossible to extract neutrinos' information using any of the traditional…
This paper presents a measurement of the polarisation of $W$ bosons from $t\bar{t}$ decays, reconstructed in events with one high-$p_{\mbox{T}}$ lepton and at least four jets. Data from $pp$ collisions at the LHC were collected at…
Tau leptons serve as an important tool for studying the production of Higgs and electroweak bosons, both within and beyond the Standard Model of particle physics. Accurate reconstruction and identification of hadronically decaying tau…
At energies that are large with respect to the electroweak scale, the electroweak corrections to scattering processes involve large logarithms that have to be resummed to obtain decent predictions. Soft-collinear effective theory (SCET) has…
We explore a possibility of optimization of the method of determination of the top quark mass from $M_{b\ell}$ distribution in semi-leptonic decays $t \to b \ell\nu$ at LHC and a future linear collider (LC). We discover that the systematic…
We propose a method for reconstructing the mass of a particle, such as the Higgs boson, decaying into a pair of tau leptons, of which one subsequently undergoes a 3-prong decay. The kinematics is solved using information from the visible…
Angular and energy distributions for leptons and bottom quarks in the process e+e- --> t tbar --> l/b ... have been calculated assuming the most general top-quark couplings. The double distributions depend both on modification of the…
Neutrinos are among the most mysterious particles in nature. Their mass hierarchy and oscillations, as well as their antiparticle properties, are being intensively studied in experiments around the world. Moreover, in many models of physics…
We examine the potential for a 10~TeV lepton collider to carry out precision measurements of the W boson mass and W boson couplings strength, i.e. the CKM matrix elements. We consider the several W boson production mechanisms and focus on…
A top-quark reconstruction method for CLIC is described. The reconstructed events are used to measure the e+ e- -> t \bar{t} cross-section as well as the forward-backward asymmetry. The results suggest that the relative measurement accuracy…