New Strongly Coupled Sector at the Tevatron and the LHC

We examine the possibility that a new strong interaction is accessible to the Tevatron and the LHC. In an effective theory approach, we consider a scenario with a new color-octet interaction with strong couplings to the top quark, as well as the presence of a strongly coupled fourth-generation which could be responsible for electroweak symmetry breaking. We apply several constraints, including the ones from flavor physics. We study the phenomenology of the resulting parameter space at the Tevatron, focusing on the the forward-backward asymmetry in top pair production, as well as in the production of the fourth-generation quarks. We show that if the excess in the top production asymmetry is indeed the result of this new interaction, the Tevatron could see the first hints of the strongly coupled fourth-generation quarks. Finally, we show that the LHC with $\sqrt{s}=7~$TeV and $1~{\rm fb}^{-1}$ integrated luminosity should observe the production of fourth-generation quarks at a level at least one order of magnitude above the QCD prediction for the production of these states.Comment: 8 pages, 12 figure

Comment on Solution of the Relativistic Dirac-Morse Problem

We do not think that the relativistic Morse potential problem has been correctly formulated and solved by Alhaidari (Phys. Rev. Lett. 87, 210405 (2001)).Comment: Revtex, 4 pages, preprint "Notas de F\'\i sica" CBPF-NF-011/02/Fev./200

N-Relaxion: Large Field Excursions from a Few Site Relaxion Model

Relaxion models are an interesting new avenue to explain the radiative stability of the Standard Model scalar sector. They require very large field excursions, which are difficult to generate in a consistent UV completion and to reconcile with the compact field space of the relaxion. We propose an N-site model which naturally generates the large decay constant needed to address these issues. Our model offers distinct advantages with respect to previous proposals: the construction involves non-abelian fields, allowing for controlled high energy behaviour and more model building possibilities, both in particle physics and inflationary models, and also admits a continuum limit when the number of sites is large, which may be interpreted as a warped extra dimension.Comment: 7 pages, 2 figures; v2: version to appear in PR

On Useful Conformal Tranformations In General Relativity

Local conformal transformations are known as a useful tool in various applications of the gravitational theory, especially in cosmology. We describe some new aspects of these transformations, in particular using them for derivation of Einstein equations for the cosmological and Schwarzschild metrics. Furthermore, the conformal transformation is applied for the dimensional reduction of the Gauss-Bonnet topological invariant in $d=4$ to the spaces of lower dimensions.Comment: 17 pages, LaTeX. The paper is intended mainly for pedagogical purposes and represents a collection of exercises concerning local conformal transformations and dimensional reduction. To be published in "Gravitation and Cosmology

Desenvolvimento de marca para produtos rurais: um estudo multicasos em São Paulo e Mato Grosso do Sul.

Resumo: Este artigo objetiva analisar a proposta de valor decorrente da identidade de marcas desenvolvidas por produtores rurais no Brasil. A análise da identidade de marcas foi baseada no modelo de planejamento da identidade de Aaker (1996). A metodologia adotada foi o estudo de casos múltiplos junto a seis produtores rurais de alimentos que criaram suas próprias marcas. Os casos contemplam dois produtores de leite, um criador de suínos, um produtor de frutas, um produtor de mel e um produtor de cachaça orgânica. Os resultados apontam para marcas conscientes de suas responsabilidades com relação aos clientes, consumidores, meio ambiente e sociedade. [Development of trademark for farm products: a study multi-case in Brazil]. Abstract: This paper aims to examine the proposal of value from the identity of the brands of foods developed by farmers in Brazil. The analysis of the identity of the brands was based on the Aaker (1996) model. The methodology was the multicase studies with six food rural producers - two producers of milk, a pig farmer, a producer of fruit, a producer of honey and a producer of organic “caipirinha”. The results indicate that brand awareness of their responsibilities with respect to customers, consumers, environment and society

Magnetic phases evolution in the LaMn1-xFexO3+y system

We have investigated the crystal structure and magnetic properties for polycrystalline samples of LaMn1-xFexO3+y, in the whole range x=0.0 to x=1.0, prepared by solid state reaction in air. All samples show the ORT-2 orthorhombic structure that suppresses the Jahn-Teller distortion, thus favoring a ferromagnetic (FM) superexchange (SE) interaction between Mn^{3+}-O-Mn^{3+}. For x=0.0 the oxygen excess (y ~ 0.09) produces vacancies in the La and Mn sites and generates a fraction around 18% of Mn^{4+} ions and 82% of the usual Mn^{3+} ions, with possible double exchange interaction between them. The Fe doping in this system is known to produce only stable Fe^{3+} ions. We find an evolution from a fairly strong FM phase with a Curie temperature T_{C} ~ 160 K, for x=0.0, to an antiferromagnetic (AFM) phase with T_{N} = 790 K, for x=1.0, accompanied by clear signatures of a cluster-glass behavior. For intermediate Fe contents a mixed-phase state occurs, with a gradual decrease (increase) of the FM (AFM) phase, accompanied by a systematic transition broadening for 0.2 < x < 0.7. A model based on the expected exchange interaction among the various magnetic-ion types, accounts very well for the saturation-magnetization dependence on Fe doping.Comment: 27 pages, 9 figure

Café & saúde humana.

Saúde e fome no Brasil; O café ao longo dos tempos; A cafeína do café; O café não contém só cafeína; Depressão, tabagismo, alcoolismo, consumo de drogas e suicídio; O café pode ajudar na prevenção da depressão e suas conseqüências; Recomendações sobre o uso do café.bitstream/item/32759/1/Cafe-e-saude-humana.pd