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Related papers: CP Violation in top pair production at an e^+e^- c…

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We investigate a possible CP violating effect in $e^+e^-$ annihilation into $t\bar t$ top quark pairs. As an illustrative example, we assume the source of the CP nonconservation is in the Yukawa couplings of a neutral Higgs boson which…

High Energy Physics - Phenomenology · Physics 2007-05-23 Darwin Chang , Wai-Yee Keung , Ivan Phillips

We investigate a potentially large CP violating asymmetry in the neutral Higgs boson decay into a heavy quark pair or a $W^+$--$W^-$ pair. The source of the CP nonconservation is in the Yukawa couplings of the Higgs boson which can contain…

High Energy Physics - Phenomenology · Physics 2009-09-01 D. Chang , W. -Y. Keung

The CP-violating effects are studied in the electron-positron annihilation to produce $t\bar{t}$ pair within the Model-III of the two-Higgs-doublet extensions, which allows flavor changing neutral currents via Higgs exchanges. Complete…

High Energy Physics - Phenomenology · Physics 2009-09-25 Chang Chao-Hsi , Han Liang , Jiang Yi , Li Xue-Qian , Ma Wen-Gan , Zhou Hong , Zhou Mian-Lai

In this talk I review how to search for CP violation in top-quark pair production and decay using T-odd correlations. I discuss two examples which illustrate many of the relevant features: CP violation in a heavy neutral Higgs boson; and CP…

High Energy Physics - Phenomenology · Physics 2022-03-02 German Valencia

CP-violating asymmetries in the processes e+e- -> t tbar and gamma gamma -> ttbar can provide information about CP-violating couplings of the top quark, whose presence would signal physics beyond the standard model. Work on studies of…

High Energy Physics - Phenomenology · Physics 2007-05-23 Saurabh D. Rindani

Due to the large mass of top quark, CP violation in the top-quark decay is sensitive to the interactions mediated by Higgs bosons. We consider CP violation in $t\rightarrow W^+ b$ decay by calculating consistently in unitary gauge the…

High Energy Physics - Phenomenology · Physics 2009-09-25 Tsutom Hasuike , Toshihiko Hattori , Toshio Hayashi , Seiichi Wakaizumi

We consider various integrated lepton charge-energy asymmetries and azimuthal asymmetries as tests of CP violation in the process $e^-e^+ \to W^-W^+$. These asymmetries are sensitive to different linear combinations of the CP violating form…

High Energy Physics - Phenomenology · Physics 2009-09-01 Darwin Chang , Wai-Yee Keung , Ivan Phillips

It is well known that $CP$-violating coupling of the Yukawa interaction of top-quark is a promising candidate of a new source of $CP$ violation effect. Precisely measurement of its $CP$ properties is crucial for understanding new physics…

High Energy Physics - Phenomenology · Physics 2019-09-17 Kai Ma

A detailed, model-independent study of CP violation at present and future electron-positron colliders is reported. Firstly, we investigate CP violation effects in $W$ boson and $t$ quark pair production in $e^+e^-$ annihilation and in…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. S. Baek , S. Y. Choi , K. Hagiwara

We study the potential of future lepton colliders to probe violation of the CP symmetry in the top quark sector. In certain extensions of the Standard Model, such as the two-Higgs-doublet model (2HDM), sizeable anomalous top quark dipole…

High Energy Physics - Experiment · Physics 2018-04-04 W. Bernreuther , L. Chen , I. García , M. Perelló , R. Poeschl F. Richard , E. Ros , M. Vos

We study consequences of CP violation in the $ht\bar{t}$ Yukawa coupling through the process $e^+e^- \to$ $h(125)t\bar{t}$. The helicity amplitudes are calculated in the $t\bar{t}$ rest frame, where the initial $e^+e^-$ current and the…

High Energy Physics - Phenomenology · Physics 2018-04-04 Kaoru Hagiwara , Hiroshi Yokoya , Ya-Juan Zheng

We provide a detailed, model-independent, study for CP violation effects due to the T-odd top-quark electric dipole moment (EDM) and weak dipole moment (WDM) in the top-quark pair production via $e^+e^-$ and two-photon annihilation at a…

High Energy Physics - Phenomenology · Physics 2016-09-06 M. S. Baek , S. Y. Choi , C. S. Kim

The process of top-quark pair production at future high-energy $e^+ e^-$ linear colliders has been investigated as a possible test of physics beyond the Standard Model. Non-standard interactions have been assumed both for the production and…

High Energy Physics - Phenomenology · Physics 2014-11-17 Bohdan Grzadkowski , Zenro Hioki

CP violation in top physics is reviewed. The Standard Model has negligible effects, consequently CP violation searches involving the top quark may constitute the best way to look for physics beyond the Standard Model. Non-standard sources…

High Energy Physics - Phenomenology · Physics 2009-09-25 David Atwood , Shaouly Bar-Shalom , Gad Eilam , Amarjit Soni

We study $CP$ violation in the process $e^+e^- \to t\bar{t} \nu\bar{\nu}$ at an $e^+e^-$-TeV collider. As the source of $CP$ violation we assume a two-Higgs doublet model with an explicitly $CP$-noninvariant Higgs potential. Sizeable…

High Energy Physics - Phenomenology · Physics 2010-11-01 A. Pilaftsis , M. Nowakowski

We report on an investigation of CP violation in (un)polarized $e^+e^-\to{\bar t}t$ resulting from an extended neutral Higgs sector or from the minimal SUSY extension of the Standard Model (SM). We consider c.m. energies from the ${\bar…

High Energy Physics - Phenomenology · Physics 2007-05-23 W. Bernreuther , A. Brandenburg , P. Overmann

We consider the possibilities of testing CP conservation in the process $e^+e^- \rightarrow ZH$. The easiest is to measure the forward-backward asymmetry of the $Z$ boson, a nonzero value of which signals CP violation. The effects of CP…

High Energy Physics - Phenomenology · Physics 2010-01-15 J. P. Ma , B. H. J. McKellar

We show that the CP-violating dipole form factors of the tau lepton can be of the order of $\alpha/\pi$ in units of the length scale set by the inverse $Z$ boson mass. We propose a few observables which are sensitive to these form factors…

High Energy Physics - Phenomenology · Physics 2016-09-06 W. Bernreuther , A. Brandenburg , P. Overmann

The energy spectra of the b and bbar quarks in e+e- -> t tbar with t -> b W (tbar -> bbar W) are calculated assuming CP violation in the production process. Expressions for the corresponding CP violating asymmetries and optimal observables…

High Energy Physics - Phenomenology · Physics 2016-08-25 A. Bartl , E. Christova , T. Gajdosik , W. Majerotto

The contribution from the R parity violating interactions in the associated production of a top quark with a charm antiquark is examined for high energy leptonic colliders. We concentrate on the reactions associated with the semileptonic…

High Energy Physics - Phenomenology · Physics 2009-10-31 Marc Chemtob , Grégory Moreau
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