2,287 research outputs found
Higgs-Radion Mixing with Enhanced Di-Photon Signal
In the context of warped scenarios in which Standard Model (SM) fields are
allowed to propagate in the bulk, we revisit the possible mixing between the IR
localized Higgs field and the Radion graviscalar. The phenomenology of the
resulting mostly-Higgs field does not suffer important deviations with respect
to the case in which all the SM is localized in the IR brane (original
Higgs-Radion mixing scenario). On the contrary, the phenomenology of the
mostly-Radion field can present important differences with respect to the
original scenario. At the LHC, the most striking effect is now the possibility
of sizeable Radion decays into photons in a mass range well beyond the ZZ and
WW thresholds, not due to dramatically enhanced couplings to photons but to
suppressed couplings to massive fields.Comment: 19 pages, 6 figure
Radion Mediated Flavor Changing Neutral Currents
In the context of a warped extra-dimension with Standard Model fields in the
bulk, we obtain the general flavor structure of the Radion couplings to
fermions and show that the result is independent on the particular nature of
the Higgs mechanism (bulk or brane localized). These couplings will be
generically misaligned with respect to the fermion mass matrix when the fermion
bulk mass parameters are not all degenerate. When the Radion is light enough,
the generic size of these tree-level flavor changing couplings will be strongly
constrained by the experimental bounds on processes. At the LHC
the possibility of a heavier Radion decaying into top and charm quarks is then
considered as a promising signal to probe the flavor structure of both the
Radion sector and the whole scenario.Comment: 4 pages, 2 figures, 1 tabl
The Invisible Higgs Decay Width in the Add Model at the LHC
Assuming flat universal extra dimensions, we demonstrate that for a light
Higgs boson the process will be observable at the level at the LHC for the
portion of the Higgs-graviscalar mixing () and effective Planck mass
() parameter space where channels relying on visible Higgs decays fail to
achieve a signal. Further, we show that even for very modest values
of the invisible decay signal probes to higher than does the
(-independent) jets/\gam + missing energy signal from graviton
radiation. We also discuss various effects, such as Higgs decay to two
graviscalars, that could become important when is of order 1.Comment: 6 pages, 2 figures, To appear in the Proceedings of the Les Houches
Workshop 2003: ``Physics at TeV Colliders'', ed. F. Boudjem
A linear moose model with pairs of degenerate gauge boson triplets
The possibility of the existence of a strongly interacting electroweak
symmetry breaking sector, as opposed to the weakly interacting light Higgs of
the Standard Model, is not yet ruled out by experiments. In this paper we make
an extensive study of a deconstructed model (or ``moose'' model) providing a
possible effective description of such a strong symmetry breaking sector, and
show its compatibility with experimental data for a wide portion of the model
parameters space. The model is a direct generalization of the previously
proposed D-BESS model.Comment: Latex file, 17 pages, 2 figures, published versio
Effective fermion couplings in warped 5D Higgsless theories
We consider a five dimensional SU(2) gauge theory with fermions in the bulk
and with additional SU(2) and U(1) kinetic terms on the branes. The electroweak
breaking is obtained by boundary conditions. After deconstruction, fermions in
the bulk are eliminated by using their equations of motion. In this way
Standard Model fermion mass terms and direct couplings to the internal gauge
bosons of the moose are generated. The presence of these new couplings gives a
new contribution to the epsilon_3 parameter in addition to the gauge boson
term. This allows the possibility of a cancellation between the two
contributions, which can be local (site by site) or global. Going back to the
continuum, we show that the implementation of local cancellation in any generic
warped metric leaves massless fermions. This is due to the presence of one
horizon on the infrared brane. However we can require a global cancellation of
the new physics contributions to the epsilon_3 parameter. This fixes relations
among the warp factor and the parameters of the fermion and gauge sectors.Comment: Latex file, 23 pages, 1 eps figur
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