Related papers: Spin Issues in t-tbar Production and Decay
We investigate spin properties of single top quark production at hadron colliders. Based on an analogy with single top production and polarized top quark decay, we reproduce in a simple way the results by G.Mahlon and S.Parke on the…
Top quark pair production by (polarized) gamma gamma collisions offers an interesting testing ground of the Standard Model and its extensions. In this Letter we present results for differential cross sections of top quark pair production…
The production rate for top quarks at the Fermilab Tevatron is presented using the exact order $\alpha_s^3$ corrected cross section and the resummation of the leading soft gluon corrections in all orders of perturbation theory.
We consider the effects in the production via gluon fusion in LHC collisions of one or two spin-zero new resonant particles $\Phi$ that decay into a top quark pair. We revisit previous analyses of the interferences between the heavy-fermion…
The top quark pairs produced at a polarized muon collider are in a (nearly) pure spin configuration. This result holds for all center-of-mass energies, and is insensitive to the next-to-leading order QCD radiative corrections. The decay…
The ttbar spin correlation at production is a fundamental prediction of QCD and a potentially incisive test of new physics coupled to top quarks. We measure the ttbar spin state in ppbar collisions at sqrt(s) = 1.96 TeV using 1001 candidate…
We present a measurement of the ratio of events with correlated t and tbar spins to the total number of ttbar events. This ratio f is evaluated using a matrix-element-based approach in events with a single lepton (electron or muon) and at…
Top pairs produced at the Large Hadron Collider exhibit quantum entanglement of their spins near threshold and for boosted, central $t \bar t$ pairs. The entanglement is maintained between the decay products, in particular between the top…
We study the production cross section of the $t$-channel single top quark at the LHC in the noncommutative space-time. It is shown that the deviation of the $t$-channel single top cross section from the Standard Model value because of…
Recent measurements of top-quark properties (excluding the top quark mass) at ATLAS and CMS are discussed. This includes latest updates of measurements of $t\bar{t}$ production asymmetries, spin correlations and $W$ helicity, as well as the…
Angular correlation of jets produced in association with a massive scalar, vector or tensor boson is crucial in the determination of their spin and CP properties. We study jet angular correlations in events with a high mass bottom quark…
Angular and energy distributions for leptons and bottom quarks in the process e^+e^- --> t t-bar --> l^{+-}/b(b-bar) ... have been calculated assuming the most general top-quark couplings. The double distributions depend both on…
We present a quantitative study on sensitivities to the top-decay anomalous couplings, taking into account realistic experimental conditions expected at Tevatron and LHC. A double angular distribution of W and charged lepton in the top…
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…
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…
Measurements of the top quark-antiquark (t t-bar) spin correlations and the top quark polarization are presented for t t-bar pairs produced in pp collisions at sqrt(s) = 8 TeV. The data correspond to an integrated luminosity of 19.5 inverse…
We compare the impact of top-quark spin polarization effects in Higgs boson production in association with top-quark pairs and in corresponding backgrounds at the LHC. Because of the spin-zero nature of the Higgs boson, one expects, in the…
Measurements of spin correlation in top quark pair production are presented using data collected with the ATLAS detector at the LHC with proton-proton collisions at a center-of-mass energy of 7 TeV, corresponding to an integrated luminosity…
Single top quark production at the Fermilab Tevatron Run II (a p \bar{p} collider with \sqrt{S} = 2 TeV) proceeds dominantly via two sub-processes, a t-channel W-gluon fusion process, and an s-channel W^* process. We show that these two…
Gluon PDFs, GPDs and TMDs play a significant role in an array of scattering processes, including SIDIS, DVCS, exclusive meson electroproduction and p - p scattering. Spin dependent gluon distributions can lead to distinctive features in the…