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Related papers: Use of Lambda_b Polarimetry in Top Quark Spin-Corr…

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This continuation of the derivation of general beam-referenced stage-two spin-correlation functions is for the analysis of top-antitop pair-production at the Tevatron and at the Large Hadron Collider. Both the gluon-production and the…

High Energy Physics - Phenomenology · Physics 2009-01-07 Charles A. Nelson , Jeffrey J. Berger , Joshua R. Wickman

We calculate the ${\cal O}(\alpha_s)$ radiative corrections to the spin dependent differential decay rates of the process $t\rightarrow b+W^+$. These are needed to study the angular distribution of the energy of hadrons produced in…

High Energy Physics - Phenomenology · Physics 2016-06-14 S. Mohammad Moosavi Nejad , Mahboobe Balali

The combination of the latest and most precise measurements of several top quark properties is presented in this paper in order to establish allowed regions on anomalous contributions to the Lorentz structure of the $Wtb$ vertex. These…

High Energy Physics - Phenomenology · Physics 2019-03-25 Frédéric Déliot , Miguel C. N. Fiolhais , António Onofre

We investigate several quantities, defined in the decays of top quark pairs, which can be used to explore non-standard Wtb interactions. Two new angular asymmetries are introduced in the leptonic decay of top (anti)quarks. Both are very…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. A. Aguilar-Saavedra , J. Carvalho , N. Castro , A. Onofre , F. Veloso

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…

High Energy Physics - Phenomenology · Physics 2015-11-02 Saurabh D. Rindani , Pankaj Sharma , Anthony W. Thomas

The polarization of the $W$ boson in $t \to W b$ decay is unambiguously predicted by the Standard Model of weak interactions and is a powerful test of our understanding of the $tbW$ vertex. The subsequent $W \to l \nu$ decay serves as a…

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

We discuss the Lambda_b-polarization of the bottom baryon Lambda_b in its production and in its decay. Standard Model predictions for b-quark polarization on the Z-peak are reviewed, including beam-quark orientation effects and O(as)…

High Energy Physics - Phenomenology · Physics 2011-01-25 J. G. K"orner

The complete set of matrix elements for all polarization configurations in top quark decays is presented including higher order QCD corrections. The analysis is done in the framework of the helicity formalism. The results can be used in a…

High Energy Physics - Phenomenology · Physics 2007-05-23 Bodo Lampe

The complete density matrix for all polarization configurations in the process B--> t tbar, where B is an off--shell Z or photon and t is the top quark, is calculated numerically including oneloop QCD corrections, i.e. virtual and real…

High Energy Physics - Phenomenology · Physics 2011-09-13 Bodo Lampe

The presented results on top quark properties include measurements of the top quark pair charge asymmetry, the top quark polarization in pair production and single top production, the W helicity in top quark decays. Results of spin…

High Energy Physics - Experiment · Physics 2015-10-06 Kelly Beernaert

Observables sensitive to top quark polarization are important for characterizing or even discovering new physics. The most powerful spin analyzer in top decay is the down-type fermion from the W, which in the case of leptonic decay allows…

High Energy Physics - Phenomenology · Physics 2014-11-19 Brock Tweedie

Measurements of several top-quark properties, obtained from the CMS data collected in 2011 and 2012 at centre-of-mass energies of 7 and 8 TeV are presented. The results include measurements of the top pair charge asymmetry, the W helicity…

High Energy Physics - Experiment · Physics 2019-08-14 Efe Yazgan

We provide a framework for the analysis of the W boson helicity in the decay of the top quark that is based on a general effective tbW coupling. Four independent coupling coefficients can be uniquely determined by the fractions of…

High Energy Physics - Phenomenology · Physics 2010-12-13 Chuan-Ren Chen , F. Larios , C. -P. Yuan

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…

High Energy Physics - Experiment · Physics 2017-12-18 ATLAS Collaboration

The large statistics of millions of hadronic Z0 decays, accumulated by the four LEP experiments between 1989 and 1995, allowed for detailed investigations of the fragmentation process. Inclusive Lambda_b baryons and Lambda hyperons at…

High Energy Physics - Experiment · Physics 2007-05-23 Thomas Kress

Fully reconstructed top-antitop-events are used to determine the fractions of right-handed and longitudinally polarized W bosons produced in top-quark decays. The helicity fractions are sensitive to the couplings and the Dirac structure of…

High Energy Physics - Experiment · Physics 2010-05-12 T. Aaltonen

The latest results on top quark physics, namely single top quark production cross sections, $W$-boson helicity and asymmetry measurements are used to probe the Lorentz structure of the $Wtb$ vertex. The increase of sensitivity to new…

To enable an evaluation of future measurements of the helicity parameters for " t --> W b " decay in regard to " T_FS violation", this paper considers the effects of an additional pure-imaginary coupling, (i g/2 Lambda) or (i g), associated…

High Energy Physics - Phenomenology · Physics 2012-08-27 Charles A. Nelson , L. J. Adler,

This paper presents measurements of the polarization of W bosons in top quark decays, derived from ttbar events with missing transverse momentum, one charged lepton and at least four jets, or two charged leptons and at least two jets. Data…

High Energy Physics - Experiment · Physics 2012-08-27 ATLAS Collaboration

The electroweak production and subsequent decay of single top quarks is determined by the properties of the $Wtb$ vertex. This vertex can be described by the complex parameters of an effective Lagrangian. An analysis of angular…

High Energy Physics - Experiment · Physics 2016-04-12 ATLAS Collaboration