795 research outputs found
Deciphering the minimum of energy of some walking technicolor models
There are quasi-conformal theories, like the Minimal and Ultraminimal
Technicolor models, which may break dynamically the gauge symmetry of the
Standard Model and at the same time are compatible with electroweak precision
data. The main characteristic of this type of models is their fermionic content
in one or more higher dimensional representations, therefore it is not
immediate to know which model leads to the most attractive channel or the
minimum vacuum energy state. We discuss the effective potential for composite
operators for these models, verifying that their vacuum energy values are
different, with the Ultraminimal model having a deeper minimum of energy.Comment: 4 pages, 2 figures, published version
Scalar bosons in Minimal and Ultraminimal Technicolor: Masses, trilinear couplings and widths
We compute masses, trilinear self-couplings and decay widths into weak bosons
of the scalar composite bosons in the case of the Minimal and Ultraminimal
technicolor models. The masses, computed via the Bethe-Salpeter equation, turn
out to be light and the trilinear couplings smaller than the one that would be
expected when compared to a fundamental Standard Model scalar boson with the
same mass. The decay widths into electroweak bosons of the Ultraminimal model
scalars bosons are much smaller than the one of the Minimal model.Comment: 15 pages, 1 figure, improved discussion, new references and typos
corrected, matchs version to be publishe
Composite Higgs Models, Technicolor and The Muon Anomalous Magnetic Moment
We revisit the muon magnetic moment (g-2) in the context of Composite Higgs
models and Technicolor, and provide general analytical expressions for
computing the muon magnetic moment stemming from new fields such as, neutral
gauge bosons, charged gauge bosons, neutral scalar, charged scalars, and exotic
charged leptons type of particles. Under general assumptions we assess which
particle content could address the excess. Moreover, we take a
conservative approach and derive stringent limits on the particle masses in
case the anomaly is otherwise resolved and comment on electroweak and collider
bounds. Lastly, for concreteness we apply our results to a particular
Technicolor model.Comment: 9 pages, 5 figure
A dynamical mechanism to explain the top-bottom quark mass hierarchy
We discuss the mass splitting between the the top and bottom quarks in a
technicolor scenario. The model proposed here contains a left-right electroweak
gauge group. An extended technicolor group and mirror fermions are introduced.
The top-bottom quark mass splitting turns out to be intimately connected to the
breaking of the left-right gauge symmetry. Weak isospin violation occurs within
the experimental limits.Comment: Changes are made in sections I, II and IV; an new figure added;
results unchanged; accepted for publication in Int. J. Mod. Phys.
Strength of the Trilinear Higgs Boson Coupling in Technicolor Models
We discuss the strength of the trilinear Higgs boson coupling in technicolor
(or composite) models in a model independent way. The coupling is determined as
a function of a very general ansatz for the technicolor self-energy, and turns
out to be equal or smaller than the one of the standard model Higgs boson
depending on the dynamics of the theory. With this trilinear coupling we
estimate the cross section for Higgs boson pair production at the LHC. This
measurement is quite improbable in the case of a heavy standard model Higgs
boson, but it will be even worse when this boson is dynamically generated.Comment: 20 pages, 4 figures, Typos correcte
Energy criterion to select the behavior of dynamical masses in technicolor models
We propose a quite general ansatz for the dynamical mass in technicolor
models. We impose on this ansatz the condition for formation of the tightest
composite boson state, or the criterion that it should lead to the deepest
minimum of energy. This criterion indicates a particular form of the
technifermion self energy.Comment: 4 pages, 3 figures; to appear in Phys. Lett.
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