251 research outputs found

    Conformal Barrier and Hidden Local Symmetry Constraints: Walking Technirhos in LHC Diboson Channels

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    We expand the previous analyses of the conformal barrier on the walking technirho for the 2 TeV diboson excesses reported by the ATLAS collaboration, with a special emphasis on the hidden local symmetry (HLS) constraints. We first show that the Standard Model (SM) Higgs Lagrangian is equivalent to the scale-invariant nonlinear chiral Lagrangian, which is further gauge equivalent to the scale-invariant HLS model, with the scale symmetry realized nonlinearly via SM Higgs as a (pseudo-) dilaton. The scale symmetry forbids the new vector boson decay to the 125 GeV Higgs plus W/Z boson, in sharp contrast to the conventional "equivalence theorem" which is invalidated by the conformality. The HLS forbids mixing between the iso-triplet technirho's, rho_{Pi} and rho_{P}, of the one-family walking technicolor (with four doublets N_D=N_F/2=4), which, without the HLS, would be generated when switching on the standard model gauging. We also present updated analyses of the walking technrho's for the diboson excesses by fully incorporating the constraints from the conformal barrier and the HLS as well as possible higher order effects: still characteristic of the one-family walking technirho is its smallness of the decay width, roughly of order Gamma/M_rho ~ [3/N_C x 1/N_D] x [Gamma/M_rho]_{QCD} ~ 70 GeV/2TeV (N_D= N_C=4), in perfect agreement with the expected diboson resonance with Gamma<100 GeV. The model is so sharply distinguishable from other massive spin 1 models without the conformality and HLS that it is clearly testable at the LHC Run II. If the 2 TeV boson decay to WH/ZH is not observed in the ongoing Run II, then the conformality is operative on the 125 GeV Higgs, strongly suggesting that the 2 TeV excess events are responsible for the walking technirhos and the 125 GeV Higgs is the technidilaton.Comment: latex, 12 eps figures, 36 pages; minor corrections made in theory part, version published in NP

    Condensate Enhancement and D-Meson Mixing in Technicolor Theories

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    Since the pioneering work of Eichten and Lane it has been known that the scale of the interactions responsible for the generation of the strange-quark mass in extended technicolor theories must, absent any "GIM-like" mechanism for suppressing flavor-changing neutral currents, be greater than of order 1000 TeV. In this note we point out that the constraint from the neutral D-meson system is now equally strong, implying that the charm quark mass must also arise from flavor dynamics at a scale this high. We then quantify the degree to which the technicolor condensate must be enhanced in order to yield the observed quark masses, if the extended technicolor scale is of order 1000 TeV. Our results are intended to provide a framework in which to interpret and apply the results of lattice studies of conformal strongly interacting gauge theories, and the corresponding numerical measurements of the anomalous dimension of the mass operator in candidate theories of "walking" technicolor.Comment: 6 pages, references added and re-ordere

    Flavor constraints in a Bosonic Technicolor model

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    Flavor constraints in a bosonic Technicolor model are considered. We illustrate different sources for their origin, and emphasize in particular the role played by the vector states present in the Technicolor model. This feature is the essential difference in comparison to an analogous model with two fundamental Higgs scalar doublets.Comment: 16 pages, 13 figure
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