14,908 research outputs found
Extracting the mass scale of a second Higgs boson from a deviation in couplings
We investigate the correlation between a possible deviation in the discovered
Higgs boson couplings from the Standard Model prediction and the mass
scale () of the next-to-lightest Higgs boson in models with
non-minimal Higgs sectors. In particular, we comprehensively study a class of
next-to-minimal Higgs sectors which satisfy the electroweak parameter to
be one at tree level. We derive an upper limit on by imposing
bounds from perturbative unitarity, vacuum stability, triviality and
electroweak precision data as functions of the deviation in the ()
couplings. Furthermore, we discuss the complementarity between these bounds and
the current LHC data, e.g., by considering direct searches for additional Higgs
bosons and indirect constraints arising from the measured signal
strengths.Comment: 37 pages, 36 figure
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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