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CP Violation in $t\to W^+ b$ Decays in Two-Higgs Doublet Model

Tsutom Hasuike·Toshihiko Hattori·Toshio Hayashi·Seiichi Wakaizumi
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Abstract

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 CP-violating up-down asymmetry of the leptons from $W$ boson decays in $t\rightarrow W^+ b$, defined by Grzcadkowski and Gunion, in the two-Higgs doublet model with CP-violating neutral sector. The asymmetry is shown to be at most of the order of $(1-3)\times 10^{-4}$ for $\tanβ=1.0$, where $\tanβ$ is the ratio of vacuum expectation values for the two neutral Higgs bosons.

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Tsutom Hasuike, Toshihiko Hattori, Toshio Hayashi, Seiichi Wakaizumi. 1996-11-12. CP Violation in $t\to W^+ b$ Decays in Two-Higgs Doublet Model. https://arxiv.org/abs/hep-ph/9611304

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