1,722 research outputs found
FCNC and non-standard soft-breaking terms in weak-scale Supersymmetry
We study the inclusion of non-standard soft-breaking terms in the minimal
SUSY extension of the SM, considering it as a model of weak-scale SUSY. These
terms modify the sfermion mass matrices, which can induce new sources of
flavour violation. Bounds on the new soft parameters can be estimated from
current data. The results are then applied to evaluate FCNC top decay t -> c +
hi (hi= h,H,A). Implications of complex soft parameters for CP violation are
also addressed.Comment: Revised version (8 pages), title changed and references corrected.
Presented at VIII Mexican Workshop on Particles and Fields, Merida (1999
Gauge-Higgs unification with brane kinetic terms
By identifying the Higgs field as an internal component of a higher
dimensional gauge field it is possible to solve the little hierarchy problem.
The construction of a realistic model that incorporates such a gauge-Higgs
unification is an important problem that demands attention. In fact, several
attempts in this direction have already been put forward. In this letter we
single out one such attempt, a 6D SU(3) extended electroweak theory, where it
is possible to obtain a Higgs mass prediction in accord with global fits. One
shortcoming of the model is its prediction for the Weinberg angle, it is too
large. We slightly modify the model by including brane kinetic terms in a way
motivated by the orbifold action on the 6D fields. We show that in this way it
is possible to obtain the correct Weinberg angle while keeping the desired
results in the Higgs sector.Comment: 11 pages, 2 figures. References added. Version to appear in Phys.
Lett.
Higgs couplings and new signals from Flavon-Higgs mixing effects within multi-scalar models
Testing the properties of the Higgs particle discovered at the LHC and
searching for new physics signals, are some of the most important tasks of
Particle Physics today. Current measurements of the Higgs couplings to fermions
and gauge bosons, seem consistent with the Standard Model, and when taken as a
function of the particle mass, should lay on a single line. However, in models
with an extended Higgs sector the diagonal Higgs couplings to up-quarks,
down-quarks and charged leptons, could lay on different lines, while
non-diagonal flavor-violating Higgs couplings could appear too. We describe
these possibilities within the context of multi-Higgs doublet models that
employ the Froggatt-Nielsen (FN) mechanism to generate the Yukawa hierarchies.
Furthermore, one of the doublets can be chosen to be of the inert type, which
provides a viable dark matter candidate. The mixing of the Higgs doublets with
the flavon field, can provide plenty of interesting signals, including: i)
small corrections to the couplings of the SM-like Higgs, ii) exotic signals
from the flavon fields, iii) new signatures from the heavy Higgs bosons. These
aspects are studied within a specific model with 3+1 Higgs doublets and a
singlet FN field. Constraints on the model are derived from the study of K and
D mixing and the Higgs search at the LHC. For last, the implications from the
latter aforementioned constraints to the FCNC top decay are presented
too.Comment: 10 pages, 3 figures and 2 tables; v2: author added, text improved;
v3: Title and Abstract slightly changed, 19 pages, references, tables and
images added, additional clarifications; matches version published by Nucl.
Phys.
A Model of Neutrino and Higgs Physics at the Electroweak Scale
We present and explore the Higgs physics of a model that in addition to the
Standard Model fields includes a lepton number violating singlet scalar field.
Based on the fact that the only experimental data we have so far for physics
beyond the Standard Model is that of neutrino physics, we impose a constraint
for any addition not to introduce new higher scales. As such, we introduce
right-handed neutrinos with an Electroweak Scale mass. We study the Higgs decay
and show that it leads to different signatures compared to
those in the Standard Model, making it possible to detect them and to probe the
nature of their couplings.Comment: 11 pages, 4 figures, 1 table. Corrected factor on eq. 17 and data
table I. Added references. Version to appear in Physics Letters
Composite Higgs models, Dark Matter and Lambda
We suggest that dark matter can be identified with a stable composite fermion
X^0, that arises within the holographic AdS/CFT models, where the Higgs boson
emerges as a composite pseudo-goldstone boson. The predicted properties of X^0
satisfies the cosmological bounds, with m_X = O(TeV). Thus, through a deeper
understanding of the mechanism of electroweak symmetry breaking, a resolution
of the Dark Matter enigma is found. Furthermore, by proposing a discrete
structure of the Higgs vacuum, one can get a distinct approach to the
cosmological constant problem.Comment: Prepared for the Proccedings of the XIII Mexican School of Particles
and Fields, Sonora (Mexico), Oct. 2-11, 2008, 8 page
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