221 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
Indirect Sensitivity to Heavy Z' Bosons at a Multi-TeV e+e- Collider
We compare the phenomenology of two models, the so-called minimal Z' and an
effective model for a SM-like Higgs realised as a composite state of a new
strong interaction, at a multi-TeV linear collider in the hypothesis that the
new physics is at a scale beyond the direct reach of the machine.Comment: 6 pages, 5 figures, to appear in the Proceedings of the International
Workshop on Future Linear Colliders LCWS201
A Concrete Composite 2-Higgs Doublet Model
We consider a Composite Higgs Model (CHM) with two isospin doublet Higgs
fields arising as pseudo Nambu-Goldstone bosons from a breaking. The main focus of this work is to
explicitly compute the properties of these Higgses in terms of the fundamental
parameters of the composite sector such as masses, Yukawa and gauge couplings
of the new spin-1 and spin-1/2 resonances. Concretely, we calculate the Higgs
potential at one-loop level through the Coleman-Weinberg mechanism from the
explicit breaking of the global symmetry by the partial
compositeness of fermions and gauge bosons. We derive then the phenomenological
properties of the Higgs states and highlight the main signatures of this
Composite 2-Higgs Doublet Model at the Large Hadron Collider, including
modifications to the SM-like Higgs couplings as well as production and decay
channels of heavier Higgs bosons. We also consider flavour bounds that are
typical of CHMs with more than one Higgs doublet.Comment: 45 pages, 16 figures, version accepted for publication in JHE
Future Electron-Positron Colliders and the 4-Dimensional Composite Higgs Model
In this note we analyse the prospects of a future electron-positron collider
in testing a particular realisation of a composite Higgs model encompassing
partial compositeness, namely, the 4-Dimensional Composite Higgs Model. We
study the main Higgs production channels for three possible energy stages and
different luminosity options of such a machine and confront our results to the
expected experimental accuracies in the various Higgs decay channels accessible
herein and, for comparison, also at the Large Hadron Collider.Comment: 24 pages, 10 figures, minor corrections for publication in JHE
Top pair production at a future machine in a composite Higgs scenario
The top quark plays a central role in many New Physics scenarios and in
understanding the details of Electro-Weak Symmetry Breaking. In the short- and
mid-term future, top-quark studies will mainly be driven by the experiments at
the Large Hadron Collider. Exploration of top quarks will, however, be an
integral part of particle physics studies at any future facility and an collider will have a very comprehensive top-quark physics program. We
discuss the possibilities of testing NP in the top-quark sector within a
composite Higgs scenario through deviations from the Standard Model in top pair
production for different Centre-of-Mass energy options of a future
machine. In particular, we focus on precision studies of the top-quark sector
at a CM energy ranging from 370 GeV up to 3 TeV.Comment: 23 pages, 10 figures; v2: minor corrections, published on JHE
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