English
Related papers

Related papers: A New Kind of Weak-Coupling in Top-Quark Physics ?

200 papers

This talk concerns some theoretical patterns of the helicity amplitudes for t --> W b decay. The patterns involve both the standard model's four decay helicity amplitudes, A_{SM}, and also the amplitudes A_{+} in the case of an additional…

High Energy Physics - Phenomenology · Physics 2007-05-23 Charles A. Nelson

Tests of the Lorentz structure of t --> W b decay will be carried out at the Tevatron, and later at the LHC and at a NLC. To quantitatively assay future measurements of competing observables, we consider the (V-A) coupling values of the…

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

To quantitatively assay future measurements of competing observables in t --> W b decay, we consider the g_{V-A} coupling values of the helicity decay parameters versus those for "(V-A)+ Single Additional Lorentz Structures". There are 2…

High Energy Physics - Phenomenology · Physics 2007-05-23 Charles A. Nelson

Most of this paper consists of the derivation of general beam-referenced stage-two spin-correlation functions for the analysis of top-antitop pair-production at the Tevatron, at the Large Hadron Collider, and/or at an International Linear…

High Energy Physics - Phenomenology · Physics 2009-01-07 Charles A. Nelson , Eric Gasparo Barbagiovanni , Jeffrey J. Berger , Elisa K. Pueschel , Joshua R. Wickman

The standard model(SM) predicts only a $g_{V-A}$ coupling in $t \to W^+ b$ decay. However, if additional Lorentz structures exist, they can manifest themselves in high energy processes such as this via non-SM values of the helicity…

High Energy Physics - Phenomenology · Physics 2011-09-13 Charles A. Nelson , Andrew M. Cohen

For the t --> W b decay mode, an intensity-ratio equivalence for two distinct Lorentz-invariant couplings is shown to be a consequence of symmetries of tWb-transformations. Three explicit tWb-transformations connect the four standard…

High Energy Physics - Phenomenology · Physics 2007-05-23 Charles A. Nelson

For the observed t --> W b decay, an intensity-ratio equivalence-theorem for two Lorentz-invariant couplings is shown to be related to symmetries of tWb-transformations. Three explicit tWb-transformations, A_{+}=M A_{SM}, ... relate the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Charles A. Nelson

Versus the standard model's t --> W b decay helicity amplitudes, three numerical puzzles occur at the 0.1 % level when one considers the amplitudes in the case of an additional (f_M + f_E) coupling of relative strength 53 GeV. The puzzles…

High Energy Physics - Phenomenology · Physics 2011-03-23 Charles A. Nelson

The most general parametrization of the $tbW$ vertex includes a right coupling $V_R$ that is zero at tree level in the standard model. This quantity may be measured at the Large Hadron Collider where the physics of the top decay is…

High Energy Physics - Phenomenology · Physics 2016-01-27 Gabriel A. González-Sprinberg , Jordi Vidal

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

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

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

Due to the absence of hadronization effects and the large top mass, top quark decay will be uniquely sensitive to fundamental electroweak physics at the Tevatron, at the LHC, and at a future linear collider. A complete measurement of the…

High Energy Physics - Phenomenology · Physics 2009-01-07 Charles A. Nelson

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

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 review and update current limits on possible anomalous couplings of the top quark to gauge bosons. We consider data from top quark decay (as encoded in the $W$-boson helicity fractions) and single-top production (in the $t$-, $s$- and…

High Energy Physics - Phenomenology · Physics 2014-06-23 M. Fabbrichesi , M. Pinamonti , A. Tonero

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 density matrix for the decay of a polarised top quark into a polarised W boson and a massive b quark, for the most general Wtb vertex arising from dimension-six gauge-invariant effective operators. We show that, in addition…

High Energy Physics - Phenomenology · Physics 2014-11-21 J. A. Aguilar-Saavedra , J. Bernabeu

The search for new physics in top quark decays at the LHC is reviewed in this paper. Results from ATLAS and CMS experiments on top quark decays within the Standard Model are presented together with the measurements of the W boson…

High Energy Physics - Experiment · Physics 2013-01-01 A. Onofre

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
‹ Prev 1 2 3 10 Next ›