1,152 research outputs found

    Gauge invariant formulation of strong WW scattering

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    Models of strong WWWW scattering in the ss-wave can be represented in a gauge invariant fashion by defining an effective scalar propagator that represents the strong scattering dynamics. The \sigma(qq \ra qqWW) signal may then be computed in U-gauge from the complete set of tree amplitudes, just as in the standard model, without using the effective WW approximation (EWA). The U-gauge ``transcription'' has a wider domain of validity than the EWA, and it provides complete distributions for the final state quanta, including experimentally important jet distributions that cannot be obtained from the EWA. Starting from the usual formulation in terms of unphysical Goldstone boson scattering amplitudes, the U-gauge transcription is verified by using BRS invariance to construct the complete set of gauge and Goldstone boson amplitudes in RξR_{\xi} gauge.Comment: single LaTeX file, no figures, 12 page

    Strong WW scattering in unitary gauge

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    A method to embed models of strong WWWW scattering in unitary gauge amplitudes is presented that eliminates the need for the effective WW approximation (EWA) in the computation of cross sections at high energy colliders.The cross sections obtained from the U-gauge amplitudes include the distributions of the final state fermions in ffffWWff \rightarrow ffWW, which cannot be obtained from the EWA. Since the U-gauge method preserves the interference of the signal and the gauge sector background amplitudes, which is neglected in the EWA, it is more accurate, especially if the latter is comparable to or bigger than the signal, as occurs for instance at small angles because of Coulomb singularities. The method is illustrated for on-shell W+W+W+W+W^+W^+ \rightarrow W^+W^+ scattering and for qqqqW+W+qq \rightarrow qqW^+W^+.Comment: 14 pages, Latex with 2 epsf-embedded postscript figure

    Inelastic Channels in the Electroweak Symmetry-Breaking Sector

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    It has been argued that if light Higgs bosons do not exist then the self--interactions of WW's become strong in the TeV region and can be observed in longitudinal WWWW scattering. We present a model with many inelastic channels in the WWWW scattering process, corresponding to the creation of heavy fermion pairs. The presence of these heavy fermions affects the elastic scattering of WW's by propagating in loops, greatly reducing the amplitudes in some charge channels. Consequently, the symmetry--breaking sector cannot be fully explored by using, for example, the W+W+W^+W^+ mode alone; all WWWWWW \rightarrow WW scattering modes must be measured.}Comment: 10 pages, phyzzx, JHU-TIPAC-92001

    Reply to Comment on "Chiral suppression of scalar glueball decay"

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    Reply to the comment of Chao, He, and Ma

    The No-Higgs Signal: Strong WW Scattering at the LHC

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    Strong WW scattering at the LHC is discussed as a manifestation of electroweak symmetry breaking in the absence of a light Higgs boson. The general framework of the Higgs mechanism -- with or without a Higgs boson -- is reviewed, and unitarity is shown to fix the scale of strong WW scattering. Strong WW scattering is also shown to be a possible outcome of five-dimensional models, which do not employ the usual Higgs mechanism at the TeV scale. Precision electroweak constraints are briefly discussed. Illustrative LHC signals are reviewed for models with QCD-like dynamics, stressing the complementarity of the W^{\pm}Z and like-charge W^+W^+ + W^-W^- channels.Comment: 16 pages, talk presented at Physics at LHC, July 13 - 17, 2004, Vienna, Austria, to be published in the proceeding

    Can the Electroweak Symmetry-breaking Sector Be Hidden?

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    In a recent paper, Chivukula and Golden claimed that the electroweak symmetry--breaking sector could be hidden if there were many inelastic channels in the longitudinal WWWW scattering process. They presented a model in which the WW's couple to pseudo--Goldstone bosons, which may be difficult to detect experimentally. Because of these inelastic channels, the WWWW interactions do not become strong in the TeV region. We demonstrate that, despite the reduced WWWW elastic amplitudes in this model, the total event rate (5000\sim 5000 extra longitudinal W+WW^+W^- pairs produced in one standard SSC year) does not decrease with an increasing number of inelastic channels, and is roughly the same as in a model with a broad high--energy resonance and no inelastic channels.Comment: 10 pages, phyzzx, JHU-TIPAC-92001

    Saturating the Bound on the Scale of Fermion Mass Generation

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    Recently, Jaeger and Willenbrock have shown that the Appelquist and Chanowitz bound on the scale of top-quark mass generation can formally be saturated in a particular limit of a two-Higgs doublet model. In this note I present an alternate derivation of their result. I perform a coupled channel analysis for f fbar to V_L V_L and V_L V_L to V_L V_L scattering and derive the conditions on the parameters required for f fbar to V_L V_L scattering to be relevant to unitarity. I also show that it is not possible to saturate the bound on fermion mass generation in the two-Higgs model while maintaining tree-level unitarity in Higgs scattering at high energies.Comment: 7 pages, Latex (minor typo fixed

    The Phenomenology of a Hidden Symmetry Breaking Sector

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    We calculate the production rate of gauge-boson pairs at the SSC in a model with a ``hidden'' electroweak symmetry breaking sector. We show that the signal of electroweak symmetry breaking is lower than the background and that we cannot necessarily rely on gauge boson pairs as a signal of the dynamics of symmetry breaking.Comment: harvmac, 8 pages (4 figures), BUHEP-92-23 new version corrects error in figure
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