2,996 research outputs found
Spontaneous CP Violation in the Next-to-Minimal Supersymmetric Standard Model Revisited
We re-examine spontaneous CP violation at the tree level in the context of
the next-to-minimal supersymmetric standard model (NMSSM) with two Higgs
doublets and a gauge singlet field. We analyse the most general Higgs potential
without a discrete Z_3 symmetry, and derive an upper bound on the mass of the
lightest neutral Higgs boson consistent with present experimental data. We
investigate, in particular, its dependence on the admixture and CP-violating
phase of the gauge singlet field, as well as on tan(beta). To assess the
viability of the spontaneous CP violation scenario, we estimate epsilon_K by
applying the mass insertion approximation. We find that a non-trivial flavour
structure in the soft-breaking A terms is required to account for the observed
CP violation in the neutral kaon sector. Furthermore, combining the
minimisation conditions for spontaneous CP violation with the constraints
coming from K0-K0bar mixing, we find that the upper bound on the lightest
Higgs-boson mass becomes stronger. We also point out that the electric dipole
moments of electron and neutron are a serious challenge for SUSY models with
spontaneous CP violation.Comment: 19 pages, LaTeX2e, 5 figures; matches the published versio
Flavour Physics and CP Violation in the Standard Model and Beyond
We present the invited lectures given at the Third IDPASC School which took
place in Santiago de Compostela in January 2013. The students attending the
school had very different backgrounds, some of them were doing their Ph.D. in
experimental particle physics, others in theory. As a result, and in order to
make the lectures useful for most of the students, we focused on basic topics
of broad interest, avoiding the more technical aspects of Flavour Physics and
CP Violation. We make a brief review of the Standard Model, paying special
attention to the generation of fermion masses and mixing, as well as to CP
violation. We describe some of the simplest extensions of the SM, emphasising
novel flavour aspects which arise in their framework.Comment: Invited talk at the Third IDPASC School 2013, January 21st - February
2nd 2013, Santiago de Compostela, Galiza, Spain; 36 pages, 8 figures, 2
tables; version with few misprints correcte
Small violations of unitarity, the phase in Bs mixing and visible t->cZ decays at the LHC
We show that it is possible to accommodate the observed size of the phase in
--, mixing in the framework of a model with violation of
unitarity. This violation is associated to the presence of a new
isosinglet quark , which mixes both with and and has a mass
not exceeding 500 GeV. The crucial point is the fact that this framework allows
for of order , to be
contrasted with the situation in the Standard Model, where is
constrained to be of order . We point out that this scenario implies
rare top decays at a rate observable at the LHC and
significantly different from unity. In this framework, one may also account for
the observed size of -- mixing without having to invoke long
distance contributions. It is also shown that in the present scenario, the
observed size of -- mixing constrains
to be of order
, which is significantly smaller than what is allowed in generic
models with violations of unitarity.Comment: 20 pages. References added. Additional observables considered,
updated numerical examples, conclusions unchange
Jarlskog-like invariants for theories with scalars and fermions
Within the framework of theories where both scalars and fermions are present,
we develop a systematic prescription for the construction of CP-violating
quantities that are invariant under basis transformations of those matter
fields. In theories with Spontaneous Symmetry Breaking, the analysis involves
the vevs' transformation properties under a scalar basis change, with a
considerable simplification of the study of CP violation in the scalar sector.
These techniques are then applied in detail to the two Higgs-doublet model with
quarks. It is shown that there are new invariants involving scalar-fermion
interactions, besides those already derived in previous analyses for the
fermion-gauge and scalar-gauge sectors.Comment: 12 pages, Latex, no figure
A case report
Benign transient hyperphosphatasemia of infancy and early childhood is a self-limiting condition characte-rized by transiently increased serum alkaline phosphatase in the absence of liver, kidney or metabolic bone diseases. It is often accidentally found in children under five years old and it might be associated with a variety of underlying clinical disorders. Its pathophysiology remains unclear. Herein, we report a case of a 4-year-old girl with a 1-year history of persistent oligoarticular Juvenile Idiopathic Arthritis, who was found to have transient hyperphosphatasemia during a periodic check-up. This clinical case underlines the importance of promptly recognizing this benign condition, which avoids unnecessary extensive investigations.publishersversionpublishe
Efeito da infestação por Haematobia irritans no peso corporal de novilhos da raça Ibagé no RS.
bitstream/item/63770/1/cr20-2001.pd
O controle da mosca das miíases ou bicheiras (Cochliomyia hominivorax).
A mosca de miíases (cujo nome científico é Cochliomyia hominivorax), em animais de sangue quente e mesmo no homem, apresenta um parasitismo obrigatório periódico, que é produzido pelas suas larvas, as quais são vulgarmente conhecidas como bicheira.bitstream/item/55722/1/ct40-2001.pd
Os programas estratégicos para o controle do carrapato dos bovinos.
No Rio Grande do Sul, tradicionalmente o controle do carrapato (cientificamente denominado de Boophilus microplus) vem sendo efetuado através de banhos sucessivos, principalmente nos períodos da primavera, verão e outono.bitstream/item/55704/1/ct43-2001.pd
Efeito da infestação por Haematobia irritans no peso corporal de fêmeas da raça Hereford no RS.
bitstream/item/63769/1/cr23-2001.pd
Refuerzo sismico de muros de mamposteria con entramado de madera
After the 1755 earthquake that destroyed Lisbon, an innovative anti-seismic structural system was developed consisting of a timber skeleton, that included timber framed masonry walls. After more than 250 years these structures need rehabilitation to face the present demands. The research presented in this paper aimed at experimentally characterizing the cyclic behaviour of timber framed walls reinforced with three different methods, namely: (i) elastic-plastic dampers on diagonal braces, (ii) reinforcement of timber connections with steel plates, (iii) application of a reinforced rendering. The elastic-plastic damper showed an unsymmetrical behaviour and some difficulties to implement in practice. The strengthening with reinforced render led to an initial stiffness increase but showed a limited deformation capacity. The walls with reinforcing steel plates at the timber connections showed the best behaviour in terms of strength, stiffness and energy dissipation.Después del terremoto de 1755 que destruyó Lisboa, un sistema estructural antisísmico muy innovador fue desarrollado. El sistema consistió en un esqueleto de madera, que incluyó la construcción de muros de mampostería con un entramado de madera. Transcurridos más de 250 años, estas estructuras necesitan rehabilitación para poder hacer frente a los requisitos estructurales actuales. La investigación presentada en este trabajo tiene como objetivo caracterizar experimentalmente el comportamiento cíclico de los muros con entramado de madera reforzados con tres métodos diferentes: (i) amortiguadores elasto-plásticos, (ii) refuerzo de las conexiones de madera con placas de acero, (iii) aplicación de un mortero reforzado. El amortiguador elasto-plástico mostró un comportamiento asimétrico y algunas dificultades para aplicarlo en la práctica. El refuerzo con mortero reforzado condujo a un aumento de la rigidez inicial, pero reveló una capacidad de deformación limitada. Los muros con placas de refuerzo de acero en las conexiones de madera mostraron el mejor comportamiento en términos de resistencia, rigidez y disipación de la energía
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