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

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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

Possible $CP$-violation in top-quark couplings is discussed. It is shown that the lepton-energy distributions in $e^+ e^- \to t\bar{t} \to \ell^+\ell^-X / \ell^\pm X$ at next linear colliders (NLC) could give us useful information for this…

High Energy Physics - Phenomenology · Physics 2016-09-06 B. Grzadkowski , Z. Hioki

Top quark production in $p\bar p$ and $e^+e^-$ collisions is enhanced by the exchange of a Higgs boson. The enhancement factors are calculated in the threshold region using the Greens function method.

High Energy Physics - Phenomenology · Physics 2011-07-19 R. Harlander , M. Jezabek , J. H. Kuehn

It is important to provide guidance on whether CP violation may be measurable in top-quark production at the Large Hadron Collider. The present work extends an earlier analysis of the non-supersymmetric Two-Higgs-Doublet Model in this…

High Energy Physics - Phenomenology · Physics 2008-11-26 Abdul Wahab El Kaffas , Wafaa Khater , Odd Magne Ogreid , Per Osland

At the LHC the CP properties of the top-quark Yukawa interaction can be probed through Higgs production in gluon fusion or in association with top quarks. We consider the possibility for both CP-even and CP-odd couplings to the top quark to…

High Energy Physics - Phenomenology · Physics 2015-06-22 Federico Demartin , Fabio Maltoni , Kentarou Mawatari , Ben Page , Marco Zaro

It has recently been shown that by measuring the transverse polarizations of the final particles in $\mu^- \to e^- e^+ e^-$, it is possible to extract information on the phases of the effective couplings leading to this decay. We examine…

High Energy Physics - Phenomenology · Physics 2010-08-12 Yasaman Farzan , Saereh Najjari

We consider the phenomenology of CP violation in a color-octet extended scalar sector for t\bar{t} production and decay at the LHC. In particular we study the effect of the two neutral color-octet scalars S_I and S_R that occur in the…

High Energy Physics - Phenomenology · Physics 2012-01-31 Xiao-Gang He , German Valencia , Hiroshi Yokoya

We report the first observation of a manifestly CP violating effect in the K(L)->pi+pi-e+e- decay mode. A large asymmetry was observed in the distribution of these decays in the CP-odd and T-odd angle phi between the decay planes of the…

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

We examine very general four-point interactions arising due to new physics contributing to the Higgs production process e+e- --> HZ. We write all possible forms for these interactions consistent with Lorentz invariance. We allow the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Kumar Rao , Saurabh D. Rindani

One of the main endeavors at future high-energy colliders is the search for the Higgs boson(s) and, once found, the probe of the fundamental properties. In particular, the charge conjugation and parity (CP) quantum numbers have to be…

High Energy Physics - Phenomenology · Physics 2009-02-16 R. M. Godbole , P. S. Bhupal Dev , A. Djouadi , M. M. Mühlleitner , S. D. Rindani

One of the Sakharov's condition for baryogenesis is the violation of both C and CP. In the Standard Model, gauge interactions break maximally C, but CP is only broken through the Yukawa couplings in the poorly understood scalar sector. In…

High Energy Physics - Phenomenology · Physics 2015-06-19 Jean-Marie Frère , Maxim Libanov , Simon Mollet

The baryon asymmetry of the Universe requires CP violation, but the Standard Model falls short by a factor of $10^{-10}$ or more. Starting from a clue at the $B$ factories, we point out that the large Yukawa couplings of the sequential…

High Energy Physics - Phenomenology · Physics 2008-10-27 Wei-Shu Hou

Appreciable CP Asymmetries (~ 10%) can arise in the reaction e+ e- -> t bar-t Z already at TREE-LEVEL in models with two Higgs doublets. For a neutral Higgs particle, h, with a mass in the range 50 GeV < m_h < 400 GeV, it may be possible to…

High Energy Physics - Phenomenology · Physics 2009-10-30 S. Bar-Shalom , D. Atwood , A. Soni

Possible CP violating effects in $Z\rightarrow$ 3 jet decays are investigated. The analysis assumes the presence of CP violating $Zq\bar qG$ couplings. The contribution of these couplings to the $Z\rightarrow q\bar qG$ decay width is…

High Energy Physics - Phenomenology · Physics 2007-05-23 P. Haberl

A mu+ mu- collider is an appealing machine to probe resonant CP-violating transitions of a CP-even Higgs particle into the Z boson or into another CP-odd Higgs scalar. These phenomena are studied within a manifestly gauge-invariant approach…

High Energy Physics - Phenomenology · Physics 2009-10-28 Apostolos Pilaftsis

We calculate the effect of new CP violating interactions parameterized by an anomalous $tbW$ coupling on CP-odd observables in B decays. We find that couplings consistent with current bounds induce observable effects in some CP asymmetries…

High Energy Physics - Phenomenology · Physics 2009-10-30 A. Abd El-Hady , G. Valencia

We study the charged t-->b W h^0 and t-->b W A^0 decays in the framework of the general two Higgs doublet model, so called model III and beyond. Here, we take the Yukawa couplings complex and introduce a new complex parameter due to the…

High Energy Physics - Phenomenology · Physics 2014-11-17 E. O. Iltan

Establishing CP violation in B0 (bar{B0}) --> l+ l- decays requires a measurement of polarization of the final lepton pair, or a precise determination of the B0 --> l+ l- and bar{B0} --> l+ l- rates. We first argue that if the amplitudes of…

High Energy Physics - Phenomenology · Physics 2014-11-18 Piotr H. Chankowski , Jan Kalinowski , Zbigniew Was , Malgorzata Worek

In the framework of QCD factorization, based on the first order of isospin violation, we study direct CP violation in the decay of $\bar{B}_{s}^{0} \to K^{0}\rho^{0}(\omega)\to K^{0}\pi^{+}\pi^{-}$ including the effect of $\rho-\omega$…

High Energy Physics - Phenomenology · Physics 2011-01-28 Gang Lü , Bao-He Yuan , Ke-Wei Wei

While CP violation in the Higgs interactions with massive vector boson is already tightly constrained, the CP nature of the Higgs interactions with fermions is far less constrained. In this work, we assess the potential of…

High Energy Physics - Phenomenology · Physics 2022-03-23 Henning Bahl , Simon Brass