62 research outputs found

    The neutral top-pion and the lepton flavor violating ZZ decays ZliljZ\to l_{i}l_{j}

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    Taking into account the constraints of the present experimental limit of the process μeγ\mu\to e\gamma on the free parameters of topcolor-assisted technicolor(TC2) models, we calculate the contributions of the neutral top-pion to the lepton flavor violating(LFV) ZZ decays ZliljZ\to l_{i}l_{j}. Our results show that the value of the branching ratio Br(Zτl)Br(Z\to \tau l) is larger than that of Br(Zμe)Br(Z\to \mu e) in all of the parameter space and there is Br(Zτμ)Br(Zτe)2×1014Br(Z\to \tau\mu)\approx Br(Z\to \tau e)\simeq 2\times 10^{-14} , which is far from the reach of present or future experiments.Comment: 12 pages and 3 figures. To be published in J. Phys.

    Non-universal gauge bosons ZZ^{\prime} and rare top decays

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    We study a new method for detecting non-universal gauge bosons ZZ' via considering their effects on rare top decays. We calculate the contributions of the non-universal gauge bosons ZZ' predicted by topcolor-assisted technicolor (TC2) models and flavor-universal TC2 models on the rare top decays tcV(V=g,γ,Z)t\longrightarrow cV(V=g,\gamma,Z) and tclilj(li,lj=τ,μt\longrightarrow cl_{i}l_{j}(l_{i}, l_{j}=\tau, \mu, or e)e). We show that the branching ratios of these processes can be significantly enhanced. Over a sizable region of the parameter space, we have Br(tcg)105Br(t\longrightarrow cg)\sim10^{-5} and Br(tcττ)107Br(t\longrightarrow c\tau\tau)\sim10^{-7}, which may approach the observable threshold of near future experiments. Non-universal gauge bosons ZZ' may be detected via the rare top decay processes at the top-quark factories such as the CERN LHC.Comment: references adde

    Multiscale Technicolor and bsγb \to s \gamma

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    Correction to the bsγb\rightarrow s\gamma branching ratio in the multiscale walking technicolor model (MWTCM) is examined. For the original MWTCM, the correction is too large to explain the recent CLEO data. We show that if topcolor is further introduced, the branching ratio in the topcolor assisted MWTCM can be in agreement with the CLEO data for a certain range of the parameters.Comment: 11 pages, Latex, no macros, 3 figures, hard copy is available upon request. to appear in Z. Phys.