1,152 research outputs found
Gauge invariant formulation of strong WW scattering
Models of strong scattering in the -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 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 gauge.Comment: single LaTeX file, no figures, 12 page
Strong WW scattering in unitary gauge
A method to embed models of strong scattering in unitary gauge
amplitudes is presented that eliminates the need for the effective
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 , 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
scattering and for .Comment: 14 pages, Latex with 2 epsf-embedded postscript figure
Inelastic Channels in the Electroweak Symmetry-Breaking Sector
It has been argued that if light Higgs bosons do not exist then the
self--interactions of 's become strong in the TeV region and can be observed
in longitudinal scattering. We present a model with many inelastic
channels in the scattering process, corresponding to the creation of heavy
fermion pairs. The presence of these heavy fermions affects the elastic
scattering of '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 mode alone; all scattering modes must be measured.}Comment: 10 pages, phyzzx, JHU-TIPAC-92001
Reply to Comment on "Chiral suppression of scalar glueball decay"
Reply to the comment of Chao, He, and Ma
The No-Higgs Signal: Strong WW Scattering at the LHC
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?
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 scattering process. They presented a model in which
the 's couple to pseudo--Goldstone bosons, which may be difficult to detect
experimentally. Because of these inelastic channels, the interactions do
not become strong in the TeV region. We demonstrate that, despite the reduced
elastic amplitudes in this model, the total event rate ( extra
longitudinal 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
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
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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