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Related papers: Top Quark Spin Polarization in ep Collision

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The D0 collaboration has performed a study of spin correlation in tt-bar production for the process tt-bar to bb-bar W^+W^-, where the W bosons decay to e-nu or mu-nu. A sample of six events was collected during an exposure of the D0…

High Energy Physics - Experiment · Physics 2008-11-26 D0 Collaboration , B. Abbott

The scalar top discovery potential has been studied with a full-statistics background simulation for sqrt(s) = 500 GeV and L = 500 fb-1. The simulation is based on a fast and realistic simulation of a TESLA detector. The large simulated…

High Energy Physics - Phenomenology · Physics 2009-09-25 M. Berggren , R. Keranen , H. Nowak , A. Sopczak

Recent measurements, in particular those on $\Lambda$ polarization and spin alignment of vector mesons in $e^+e^-$ annihilation at LEP, and those on the azimuthal asymmetry at HERA, have attracted much attention on the spin effects in high…

High Energy Physics - Phenomenology · Physics 2009-11-07 Zuo-tang Liang

After a brief comment on the role of top quark in models of electroweak symmetry breaking (EWSB), I shall discuss what we know about top quark interaction and how to improve that knowledge. Since bottom quark is the weak isospin partner of…

High Energy Physics - Phenomenology · Physics 2007-05-23 C. -P. Yuan

The recent data on the polarization of vector meson at LEP show that the vector mesons favor the helicity zero state. We calculate the helicity density matrix of vector meson which contains a polarized fragmenting quark by adding the spin…

High Energy Physics - Phenomenology · Physics 2009-11-07 Xu Qing-hua , Liu Chun-xiu , Liang Zuo-tang

We investigate the effects of scalar and vector unparticles on top quark spin correlations via the process $e^{+}e^{-}\to t \bar{t}$. In addition to the Standard Model diagrams, there is a new contribution to top-antitop quark production…

High Energy Physics - Phenomenology · Physics 2010-04-30 B. Sahin

A comprehensive review of the recent results on measurements of single top-quark production cross-sections at $\sqrt{s} =$ 7, 8 and 13 TeV performed by the ATLAS and CMS Collaborations is presented. The cross-section measurements include…

High Energy Physics - Experiment · Physics 2017-09-11 Carlos Escobar

We establish the existence of the top quark using a 67 pb^-1 data sample of Pbar-P collisions at Sqrt(s) = 1.8 TeV collected with the Collider Detector at Fermilab (CDF). Employing techniques similar to those we previously published, we…

High Energy Physics - Experiment · Physics 2012-08-27 The CDF Collaboration

The collider experiments at the Tevatron and the LHC will allow for detailed investigations of the properties of the top quark. This requires precise predictions of the hadronic production of $t\bar t$ pairs and of their subsequent decays.…

High Energy Physics - Phenomenology · Physics 2009-11-07 W. Bernreuther , A. Brandenburg , Z. G. Si , P. Uwer

The uncertainty of $t\bar{t}$ production cross section measurement at LHC is at a-few-percent level which still allows the stop pair production $\tilde{t}\tilde{t}^{*}$ with identical final states $2b+\ell+nj+{E}_{T}$. In this paper, we…

High Energy Physics - Phenomenology · Physics 2014-04-23 Xue-Qian Li , Zong-Guo Si , Kai Wang , Liucheng Wang , Liangliang Zhang , Guohuai Zhu

We consider, both for unpolarized and longitudinally polarized electron beams, the production of a top quark pair in e+e- collisions with subsequent semileptonic top and nonleptonic anti-top decay and vice versa and investigate optimized…

High Energy Physics - Phenomenology · Physics 2015-06-25 Werner Bernreuther , Peter Overmann

A review of the recent results on measurements of top quark properties in single top quark events using data samples of proton proton collisions produced by the LHC at sqrt(s) = 7 and 8 TeV and collected by ATLAS and CMS detectors is…

High Energy Physics - Experiment · Physics 2016-12-01 Javier Jiménez Peña

Present limits on the top mass from LEP1 and Tevatron point to a top quark that is considerably heavier than the $W$ vector boson in the standard model. Hence, e+e- colliders with \sqrt{s} \simeq 300 GeV (the c.m. energy foreseen at the…

High Energy Physics - Phenomenology · Physics 2009-10-22 S. Ambrosanio , B. Mele

An optimal-observable analysis of the angular and energy distributions of the leptons and bottom quarks in the process e+e- --> tt-bar --> l^{+-}/b(b-bar)... has been performed in order to measure the most general top-quark couplings to…

High Energy Physics - Phenomenology · Physics 2015-03-19 Bohdan Grzadkowski , Zenro Hioki

Top quark electroweak interactions serve as a sensitive probe for beyond-Standard-Model physics, potentially exhibiting significant deviations from Standard Model predictions and offering crucial tests of fundamental symmetries in…

High Energy Physics - Phenomenology · Physics 2025-12-16 Xu-Hui Jiang , Yiming Liu , Bin Yan

In ongoing and upcoming hadron collider experiments, top quark physics will play an important role in testing the Standard Model and its possible extensions. In this work we present analytic results for the differential cross sections of…

High Energy Physics - Phenomenology · Physics 2011-05-05 W. Bernreuther , A. Brandenburg , Z. G. Si , P. Uwer

The spin alignment of vector meson produced in high energy reactions is determined by the spin-dependent fragmentation function $D_{1LL} (z,\mu_f)$ that is shown to be independent of the polarization of the fragmenting quark. In this paper,…

High Energy Physics - Phenomenology · Physics 2021-02-03 Kai-bao Chen , Zuo-tang Liang , Yu-kun Song , Shu-yi Wei

We investigate the single top quark production with the exchange of unparticles through high energy photon-photon collision $\gamma \gamma\to t \bar c$. The effects of unparticles on the scattering cross sections for different polarization…

High Energy Physics - Phenomenology · Physics 2009-07-26 T. M. Aliev , K. O. Ozansoy

We know there is new physics at the electroweak scale, but we don't know what it is. Right now, the top quark is our only window on to this physics. In almost all models of electroweak symmetry breaking, top either couples strongly to new…

High Energy Physics - Experiment · Physics 2007-05-23 John Womersley

Top quark pair spin correlation measurements performed by the ATLAS experiment using $pp$ collisions at the CERN Large Hadron Collider are summarized. Moreover, the measurement of a specific observable $D$ related to top quark pair spin…

High Energy Physics - Experiment · Physics 2026-02-04 Roman Lysak