Vertex operators and soliton solutions of affine Toda model with U(2) symmetry

The symmetry structure of the non-Abelian affine Toda model based on the coset SL(3)/SL(2) circle times U(1) is studied. It is shown that the model possess non-Abelian Noether symmetry closing into a q-deformed SL(2) circle times U(1) algebra. Specific two-vertex soliton solutions are constructed.

Local duality and charge symmetry violation in quark distributions

We use local quark-hadron duality to calculate the nucleon structure function as seen by neutrino and muon beams. Our result indicates a possible signal of charge symmetry violation at the parton level in the very large x region.

Gravitation and the local symmetry group of space-time

According to general relativity, the interaction of a matter field with gravitation requires the simultaneous introduction of a tetrad field, which is a field related to translations, and a spin connection, which is a field assuming values in the Lie algebra of the Lorentz group. These two fields, however, are not independent. By analyzing the constraint between them, it is concluded that the relevant local symmetry group behind general relativity is provided by the Lorentz group. Furthermore, it is shown that the minimal coupling prescription obtained from the Lorentz covariant derivative coincides exactly with the usual coupling prescription of general relativity. Instead of the tetrad, therefore, the spin connection is to be considered as the fundamental field representing gravitation.

Chiral symmetry and pion-nucleon scattering

In this work, we study the influence of the way pious couple to nucleons in perturbative calculation of an observable in the pion-nucleon scattering.

Search for supersymmetry with gauge-mediated breaking in diphoton events at D0

We report the results of a search for supersymmetry (SUSY) with gauge-mediated breaking in the missing transverse energy distribution of inclusive diphoton events using 263 pb(-1) of data collected by the D0 experiment at the Fermilab Tevatron Collider in 2002-2004. No excess is observed above the background expected from standard model processes, and lower limits on the masses of the lightest neutralino and chargino of about 108 and 195 GeV, respectively, are set at the 95% confidence level. These are the most stringent limits to date for models with gauge-mediated SUSY breaking with a short-lived neutralino as the next-to-lightest SUSY particle.

Dual superconformal symmetry, and the amplitude/Wilson loop connection

We show that tree level superstring theories on certain supersymmetric backgrounds admit a symmetry which we call "fermionic T-duality". This is a non-local redefinition of the fermionic worldsheet fields similar to the redefinition we perform on bosonic variables when we do an ordinary T-duality. This duality maps a supersymmetric background to another supersymmetric background with different RR fields and a different dilaton. We show that a certain combination of bosonic and fermionic T-dualities maps the full superstring theory on AdS(5) x S-5 back to itself in such a way that gluon scattering amplitudes in the original theory map to something very close to Wilson loops in the dual theory. This duality maps the "dual superconformal symmetry" of the original theory to the ordinary superconformal symmetry of the dual model. This explains the dual superconformal invariance of planar scattering amplitudes of N = 4 super Yang Mills and also sheds some light on the connection between amplitudes and Wilson loops. In the appendix, we propose a simple prescription for open superstring MHV tree amplitudes in a flat background.

ON FERMION MASSES and MIXING IN A MODEL WITH A(4) SYMMETRY

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A symmetry reduction technique for higher order Painleve systems

The symmetry reduction of higher order Painleve systems is formulated in terms of Dirac procedure. A set of canonical variables that admit Dirac reduction procedure is proposed for Hamiltonian structures governing the A(2M)((1)) and A(2M-1)((1)) Painleve systems for M = 2,3,.... (C) 2012 Elsevier B.V. All rights reserved.

Three-Higgs-doublet model with A(4) symmetry

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Natural Peccei-Quinn symmetry in the 3-3-1 model with a minimal scalar sector

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Supersymmetry of Affine Toda Models as Fermionic Symmetry Flows of the Extended mKdV Hierarchy

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Breaking down the Fermi acceleration with inelastic collisions

The phenomenon of Fermi acceleration is addressed for a dissipative bouncing ball model with external stochastic perturbation. It is shown that the introduction of energy dissipation (inelastic collisions of the particle with the moving wall) is a sufficient condition to break down the process of Fermi acceleration. The phase transition from bounded to unbounded energy growth in the limit of vanishing dissipation is characterized.

Joint Experimental and Theoretical Analysis of Order Disorder Effects in Cubic BaZrO3 Assembled Nanoparticles under Decaoctahedral Shape

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cervicovaginal aerobic microflora of women with spontaneous abortion or preterm delivery in Araraquara-Brazil

Rotina bacteriológica do conteúdo vaginal e cervical de 22 mulheres com histórico de aborto recente ou ruptura precoce das membranas foi realizada. Chlamydia trachomatis, Streptococcus pyogenes, Streptococcus agalactiae, Candida sp e Gardnerella vaginalis foram isolados em 54,5% (12) das pacientes. Apesar de Ureaplasma urealyticum ter sido frequentemente encontrado (45,5%), somente em 5 das 22 mulheres foi o único microrganismo presente nos materiais analisados. Esses resultados chamam a atenção para a importância de investigação quantitativa bem como qualitativa da microbiota genital em gestantes, tendo em vista ter consequências na gestação.

Effects of desflurane, sevoflurane and isoflurane on pulmonary shunt in dogs during spontaneous ventilation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)