50,928 research outputs found
Estaquia em espécies cítricas monoembriônicas autoincompatíveis: uma alternativa para a caracterização citogenética de variedades do Banco Ativo de Germoplasma (BAG) de Citros.
O gênero Citrus L. (família Rutaceae) é formado tipicamente por espécies poliembriônicas, cujas sementes apresentam um embrião zigótico (híbrido) e um ou vários nucelares (apomíticos). Entretanto, alguns representantes deste grupo são monoembriônicos e autoincompatíveis, fato que leva à formação de seedlings exclusivamente de origem híbrida
Spontaneous CP violation in the 3-3-1 model with right-handed neutrinos
We implement the mechanism of spontaneous CP violation in the 3-3-1 model
with right-handed neutrinos and recognize their sources of CP violation. Our
main result is that the mechanism works already in the minimal version of the
model and new sources of CP violation emerges as an effect of new physics at
energies higher than the electroweak scale.Comment: Major changes in the quark sector, electronic dipole moment of the
neutron was evaluated, accepted for publication in the physical review
Majorana Dark Matter in Minimal Higgs Portal Models after LUX
We consider the Singlet Majorana fermion dark matter model, in which the
standard model particles interact with the dark sector through the mixing of a
singlet scalar and the Higgs boson. In this model both the dark matter and the
singlet scalar carry lepton number, the latter being a bilepton. We suppose the
existence of a symmetry, remnant of some high energy local symmetry
breaking, that stabilizes the Majorana fermion. We analyzed the parameter space
of this model and found that the lepton number symmetry breaking scale, drove
by the singlet scalar, is constrained to be within hundreds to thousands of
GeV, so as to conform with the observed dark matter relic density. Finally, we
address the direct detection and invisible Higgs decay complementarity,
confronting our model with recent LUX and LHC constraints, as well as XENON1T
prospects.Comment: 20 pages, 12 figure
Neutrino Mixing and the Minimal 3-3-1 Model
In the minimal 3-3-1 model charged leptons come in a non-diagonal basis.
Moreover the Yukawa interactions of the model lead to a non-hermitian charged
lepton mass matrix. In other words, the minimal 3-3-1 model presents a very
complex lepton mixing. In view of this we check rigorously if the possible
textures of the lepton mass matrices allowed by the minimal 3-3-1 model can
lead or not to the neutrino mixing required by the recent experiments in
neutrino oscillation.Comment: two references add, minor chages, accepted for publication in MPL
Realizing the supersymmetric inverse seesaw model in the framework of R-parity violation
If, on one hand, the inverse seesaw is the paradigm of TeV scale seesaw
mechanism, on the other it is a challenge to find scenarios capable of
realizing it. In this work we propose a scenario, based on the framework of
R-parity violation, that realizes minimally the supersymmetric inverse seesaw
mechanism. In it the energy scale parameters involved in the mechanism are
recognized as the vacuum expectation values of the scalars that compose the
singlet superfields and . We develop also the scalar sector
of the model and show that the Higgs mass receives a new tree-level
contribution that, when combined with the standard contribution plus loop
correction, is capable of attaining GeV without resort to heavy stops.Comment: Minor modification of the text. Final version to be published in PL
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