Calculable lepton masses, seesaw relations, and four neutrino mixings in a 3-3-1 model with an extra U(1) symmetry

We propose a scheme in which the masses of the heavier leptons obey seesaw type relations. The light lepton masses, except the electron and the electron neutrino ones, are generated by one loop level radiative corrections. We work in a version of the 3-3-1 electroweak model that predicts singlets (charged and neutral) of heavy leptons beyond the known ones. An extra U(1)(Omega) symmetry is introduced in order to avoid the light leptons getting masses at the tree level. The electron mass induces an explicit symmetry breaking at U(1)(Omega). We discuss also the mixing matrix among four neutrinos. The new energy scale required is not higher than a few TeV.

Magnetic field effects on the conductivity of organic bipolar and unipolar devices at room temperature

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

Estimativa da composição corporal e análise de concordância entre analisadores de impedância bioelétrica bipolar e tetrapolar

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

Neutrino masses through a type II seesaw mechanism at TeV scale

In this work we show that we can generate neutrino masses through the type II seesaw mechanism working at TeV scale in the context of a 331 model. (C) 2001 Published by Elsevier B.V. B.V.

Seesaw tau lepton mass and calculable neutrino masses in a 3-3-1 model

In this work we show that in a version of the 3-3-1 model proposed by Duong and Ma, in which the introduction of a scalar sextet is avoided by adding a singlet heavy charged lepton, the tau lepton gains mass through a seesawlike mechanism. We also show how to generate neutrino masses at the one-loop level, and give the respective Maki-Nakagawa-Sakata mixing matrices for a set of the parameters. We also consider the effect of adding a singlet right-handed neutrino.

Neutrino masses through the seesaw mechanism in 3-3-1 models

Some years ago it was shown by Ma that in the context of the electroweak standard model there are, at the tree level, only three ways to generate small neutrino masses by the seesaw mechanism via one effective dimension-five operator. Here we extend this approach to 3-3-1 chiral models showing that in this case there are several dimension-five operators and we also consider their tree level realization.

Search for heavy lepton partners of neutrinos in proton-proton collisions in the context of the type III seesaw mechanism

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Anomaly-free constraints in neutrino seesaw models

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

Transtorno bipolar do humor e gênero

Although the bipolar disorder (BD) occurs almost with the same frequency in both genders, the phenomenology and the outcome of the illness differ between them. Nevertheless, there is evidence that women with BD show, more than men, delayed beginning, especially in their fifth decade, more rapid cycling outcome, more depressive episodes, more dysphoric mania, more mixed states and more BD type II. Even so, the findings are not always consistent. Although the risk of comorbidities in BD includes, for both the sorts, excessive alcoholic consumption and drugs, bipolar men would have greater probability of being alcohol dependent, of not seeking treatment and of committing suicide. Suggested hypotheses to explain such differences vary from those centered in cultural or psychological aspects to those that focus on the steroids hormones, and other hormones such as cortisol, thyroid hormones and even on the cerebral anatomy. The reproductive cycle (menstrual cycle, pregnancy and menopause) influences on the BD phenomenology and its relevance to the therapeutical options in the treatment of the BD in women are presented in the last part of this review. Further investigations must to be done in order to clarify this controversy. However, up to now the data indicate that estrogen therapy is not to be primarily indicated to prevent depression, Alzheimer disease or cognition impairment.

Avaliação e comparação da dor e da resposta inflamatória pós-cirúrgica em cadelas submetidas à ovário-histerectomia laparoscópica com único portal; realizada com pinça bipolar com corte e coagulação simultâneos ou por miniceliotomia com ganho de Snook

Pós-graduação em Cirurgia Veterinária - FCAV