Timelike and spacelike hadron form factors, Fock state components and light-front dynamics

A unified description of spacelike and timelike hadron form factors within a light-front model was successfully applied to the pion. The model is extended to the nucleon to study the role of $q \bar q$ pair production and of nonvalence components in the nucleon form factors. Preliminary results in the spacelike range $0 \le Q^2 \le 10 ~ (GeV/c)^2$ are presented.Comment: 4 pages, espcrc1.sty. proceedings of FB XVIII (August 2006, Brazil), to be published in Nucl. Phys.

Electromagnetic Hadron Form Factors and Higher Fock Components

Investigation of the spacelike and timelike electromagnetic form factors of hadrons, within a relativistic microscopical model characterized by a small set of hypothesis, could shed light on the components of hadron states beyond the valence one. Our relativistic approach has been successfully applied first to the pion and then the extension to the nucleon has been undertaken. The pion case is shortly reviewed as an illustrative example for introducing the main ingredients of our approach, and preliminary results for the nucleon in the spacelike range $-10 (GeV/c)^2\le q^2 \le 0$ are evaluated.Comment: 8 pages, 6 figs, espcrc1.sty included. Proceedings of Fifth International Conference on Perspectives In Hadronic Physics, ICTP, May 22-26, 200

Electromagnetic form factors of the nucleon in spacelike and timelike regions

An approach for a unified description of the nucleon electromagnetic form factors in spacelike and timelike regions is presented. The main ingredients of our model are: $i)$ a Mandelstam formula for the matrix elements of the nucleon electromagnetic current; $ii)$ a 3-dimensional reduction of the problem on the Light-Front performed within the so-called {\tt Propagator Pole Approximation} ({\bf PPA}), which consists in disregarding the analytical structure of the Bethe-Salpeter amplitudes and of the quark-photon vertex function in the integration over the minus components of the quark momenta; $iii)$ a dressed photon vertex in the $q\bar{q}$ channel, where the photon is described by its spin-1, hadronic component.Comment: 8 pages, 9 figs., macro added. Proceedings of the XI Conf. on Problems in Theoretical Nuclear Physics, Cortona, Oct. 11-14, 200

Instruções para o cultivo da acerola.

bitstream/item/44461/1/CPATC-DOCUMENTOS-6-INSTRUCOES-PARA-O-CULTIVO-DA-ACEROLA-FL-13124.pd

Parâmetros fisiológicos em genótipos de amendoim inoculados com BRADYRHIZOBIUM.

Dissertação (Mestrado em Ciências Agrárias) - Universidade Estadual da Paraíba, Centro de Ciências Humanas e Agrárias, Campina Grande, PB. Orientadora: Roseane Cavalcanti dos Santos - Embrapa Algodão

Topological insulator particles as optically induced oscillators: towards dynamical force measurements and optical rheology

We report the first experimental study upon the optical trapping and manipulation of topological insulator (TI) particles. By virtue of the unique TI properties, which have a conducting surface and an insulating bulk, the particles present a peculiar behaviour in the presence of a single laser beam optical tweezers: they oscillate in a plane perpendicular to the direction of the laser propagation, as a result of the competition between radiation pressure and gradient forces. In other words, TI particles behave as optically induced oscillators, allowing dynamical measurements with unprecedented simplicity and purely optical control. Actually, optical rheology of soft matter interfaces and biological membranes, as well as dynamical force measurements in macromolecules and biopolymers, may be quoted as feasible possibilities for the near future.Comment: 6 pages, 5 figures. Correspondence and requests for Supplementary Material should be addressed to [email protected]

Avaliação de genótipos de feijão para recomendação de cultivares no Estado do Rio de Janeiro.

Considerando que o processo de seleção de cultivares é contínuo, buscando selecionar materiais cada vez mais adaptados e que atendam as exigências do mercado, em 2010 a PESAGRO-RIO em parceria com a EMBRAPA-CNPAF, realizou dois testes de adaptação local (TAL) e duas Unidades Demonstrativas em locais representativos do Norte Fluminense.CONAFE

Cultivo da mamona (Ricinus communis L.) consorciada com feijão-caupi (Vigna unguiculata (L.) Walp) no Semi-Árido.

Caracterizacão do semi-árido nordestino; Clima; Solo e adubacão; Cultivares recomendadas das duas culturas; Mamona; Feijão-caupi; Espaçamentos, populações de plantas, profundidade de plantio e desbaste; Doenças e métodos de controle; Pragas da mamoneira e do feijão-caupi; Na mamoneira; No feijão-caupi; Pragas subterrâneas; Pragas da parte aérea; Pragas dos grãos armazenados; Tratos culturais; Colheita, beneficiamento e armazenamento; Poda da mamoneira e replantio do feijão-caupi; Coeficientes técnicos.bitstream/item/36688/1/Doc740001.pd