Dynamically Induced Spontaneous Symmetry Breaking in 3-3-1 Models

We show that in SU(3)_C X SU(3)_L X U(1)_N (3-3-1) models embedded with a singlet scalar playing the role of the axion, after imposing scale invariance, dynamical symmetry breaking of Peccei-Quinn symmetry occurs through the one-loop effective potential for the singlet field. We, then, analyze the structure of spontaneous symmetry breaking by studying the new scalar potential for the model, and verify that electroweak symmetry breaking is tightly connected to the 3-3-1 breaking by the strong constraints among their vacuum expectation values. This offers a valuable guide to write down the correct pattern of symmetry breaking for multi-scalar theories. We also obtained that the accompanying massive pseudo-scalar, instead of acquiring mass of order of Peccei-Quinn scale as we would expect, develops a mass at a much lower scale, a consequence solely of the dynamical breaking.Comment: 12 pages, typos corrected, improved text, conclusions unchange

Perfil sócio-econômico e tecnológico dos produtores de soja no Paraná.

Amostragenm e coleta dos dados; Modelo de analise; Analise e discussao dos dados: Distribuicao e uso da terra; Infra-estrutura economica e social; Mao-de-obra; Maquinas, equipamentos e animais; Sistemas de producao; Indicadores de administracao rural; Cooperativismo; Tecnologia e uso de insumos; Calcario; Fertilizantes; Adubacao verde; Descompactacao do solo; Metodos de manejo dos solos; Rotacao de culturas; Alternativas de inverno no Parana; Manipulacao de produtos quimicos; Uso de herbicidas e principais ervas daninhas; Pragas de soja e produtos quimicos utilizados; Doencas da soja e seu controle; Perdas na colheita; Sementes de soja.bitstream/item/77838/1/CNPSO-DOC.-38-89.pd

Spin filtering in nanowire directional coupler

The spin transport characteristics of a nanowire directional electronic coupler have been evaluated theoretically via a transfer matrix approach. The application of a gate field in the region of mixing allows for control of spin current through the different leads of the coupler via the Rashba spin-orbit interaction. The combination of spin-orbit interaction and applied gate voltages on different legs of the coupler give rise to a controllable modulation of the spin polarization. Both structural factors and field strength tuning lead to a rich phenomenology that could be exploited in spintronic devices.Comment: 9 pages, 4 figure

Phase diagram of the antiferromagnetic XY model in two dimensions in a magnetic field

The phase diagram of the quasi-two-dimensional easy-plane antiferromagnetic model, with a magnetic field applied in the easy plane, is studied using the self-consistent harmonic approximation. We found a linear dependence of the transition temperature as a function of the field for large values of the field. Our results are in agreement with experimental data for the spin-1 honeycomb compound BaNi_2V_2O_3Comment: 3 page

Aspectos qualitativos dos frutos de bananeira resistentes à sigatoka-negra no Estado do Amapá.

Cultivar caipira; Cultivar Thap maeo; Cultivar FHIA 18; Cultivar FHIA 01; Cultivar FHIA 21; Híbrido PV 0344.bitstream/item/70887/1/AP-2005-aspectos-qualitativos-bananeira.pd

O uso de planilha eletrônica na administracão rural: um modelo de custos de producão.

Planilha eletronica; O modelo "custo de producao".bitstream/item/23242/1/Doc27.pd

Homogeneous metallicities and radial velocities for Galactic globular clusters. II. New CaT metallicities for 28 distant and reddened globular clusters

Although the globular clusters in the Milky Way have been studied for a long time, a significant fraction of them lack homogeneous metallicity and radial velocity measurements. In an earlier paper we presented the first part of a project to obtain metallicities and radial velocities of Galactic globular clusters from multiobject spectroscopy of their member stars using the ESO Very Large Telescope. In this paper we add metallicities and radial velocities for a new sample of 28 globular clusters, including in particular globular clusters in the MW halo and the Galactic bulge. Together with our previous results, this study brings the number of globular clusters with homogeneous measurements to $\sim 69$ \% of those listed in the W. Harris' catalogue. As in our previous work, we have used the CaII triplet lines to derive metallicities and radial velocities. For most of the clusters in this study, this is the first analysis based on spectroscopy of individual member stars. The metallicities derived from the CaII triplet are then compared to the results of our parallel study based on spectral fitting in the optical region and the implications for different calibrations of the CaII triplet line strengths are discussed. We also comment on some interesting clusters and investigate the presence of an abundance spread in the globular clusters here. A hint of a possible intrinsic spread is found for NGC 6256, which therefore appears to be a good candidate for further study.Comment: 13 pages, 9 figures, accepted for publication in Astronomy and Astrophysic