Radion-Higgs mixing effects on bounds from LHC Higgs boson searches

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

Search for a narrow t(t)over-bar resonance in p(p)over-bar collisions at root s=1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Quark matter in a QCD Coulomb gauge quark model

In this communication we present results of a study of chiral symmetry in quark matter using an effective Coulomb gauge QCD Hamiltonian. QCD in Coulomb gauge is convenient for a variational approach based on a quasiparticle picture for the transverse gluons, in which a confining Coulomb potential arises naturally. We show that such an effective Hamiltonian predicts chiral restoration at too low quark densities. Possible reasons for such deficiency are discussed.

Langevin dynamics of the deconfinement transition for pure gauge theory

We investigate the effects of dissipation in the deconfinement transition for pure SU(2) and SU(3) gauge theories. Using an effective theory for the order parameter, we study its Langevin evolution numerically. Noise effects are included for the case of SU(2). We find that both dissipation and noise have dramatic effects on the spinodal decomposition of the order parameter and delay considerably its thermalization. For SU(3) the effects of dissipation are even larger than for SU(2).

Search for resonances in the dilepton mass distribution in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Hadron-hadron interactions in Coulomb gauge QCD

We describe the derivation of an effective Hamiltonian which involves explicit hadron degrees of freedom and consistently combines chiral symmetry and color confinement. We use a method known as Fock-Tani (FT) representation and a quark model formulated in the context of Coulomb gauge QCD. Using this Hamiltonian, we evaluate the dissociation cross section of J/psi in collision with rho.

Domínios do café: ferrovias, exportação e mercado interno em São Paulo (1888-1917)

Não obstante o peso decisivo das receitas geradas pelo café para os balanços financeiros das ferrovias paulistas entre 1888 e 1917, e a centralidade da atividade cafeeira na economia paulista de então, discute-se neste artigo a especialização relativa ao nível da produção verificada em São Paulo e a questão dos fretes das ferrovias neste cenário. Parte-se da ideia de que a cafeicultura, em seu desenvolvimento, demandava a diversificação de culturas agrícolas, pois as unidades básicas de produção - as fazendas de café - não se caracterizavam unicamente pela monocultura, sendo que os nexos entre uma produção voltada à exportação e outra voltada ao mercado interno davam-se nas relações de trabalho estabelecidas entre contratantes e contratados, e nas formas pelas quais os fazendeiros expropriavam aqueles que se subordinavam aos seus interesses. Verifica-se no caso estudado o aumento simultâneo das quantidades de café e de alimentos transportadas e transacionadas pela Cia. Mogiana nos marcos da periodização proposta; porém, percebe-se estreita dependência em relação à receita gerada pelo transporte de café. Aponta-se, ainda, a especialização absoluta ao nível do crédito e da circulação (transportes) que caracterizavam este complexo econômico.

CAUSAL PRESCRIPTION FOR THE LIGHT-CONE GAUGE

We present a prescription for light-cone gauge singularities which embeds in it causality and show that it results in simpler and less demanding integrals to be performed.

EVALUATING ONE-LOOP LIGHT-CONE INTEGRALS BY COVARIANTIZING THE GAUGE-DEPENDENT POLE

Making sure that causality be preserved by means of ''covariantizing'' the gauge-dependent singularity in the propagator of the vector potential A(mu)(x), we show that the evaluation of some basic one-loop light-cone integrals reproduce those results obtained through the Mandelstam-Leibbrandt prescription. Moreover, such a covariantization has the advantage of leading to simpler integrals to be performed in the cone variables (the bonus), although, of course, it introduces an additional alpha-parameter integral to be performed (the price to pay).

Comments on regularization ambiguities and local gauge symmetries

We study the regularization ambiguities in an exact renormalized (1 + 1)-dimensional field theory. We show a relation between the regularization ambiguities and the coupling parameters of the theory as well as their role in the implementation of a local gauge symmetry at quantum level.

Neutrinos and electromagnetic gauge invariance

We examine a recently proposed connection constraining U(1)(em) electromagnetic gauge invariance and the nature of neutrino mass terms in the framework of G(0) = SU(3)(C) x G(W) x U(1)(N) gauge extensions of the standard model where G(W) denotes the weak isospin special unitary extended groups. We show that in a large class of G(0) models there is a unique fermion representation content and scalar fields which select the neutrino mass terms. Noteworthy. even though there are mathematically equivalent representation contents then can be different aspects concerning the physical consequences which are not a mere truism.

LEPTON MASSES IN AN SU(3)L-CIRCLE-TIMES-U(1)N GAUGE-MODEL

The SU(3)cxSU(3)LxU(1)N model of Pisano and Pleitez extends the standard model in a particularly nice way, so that, for example, the anomalies cancel only when the number of generations is divisible by 3. The original version of the model has some problems accounting for the lepton masses. We resolve this problem by modifying the details of the symmetry-breaking sector in the model.