Study of psi' and chi_c decays as feed-down sources of J/psi hadro-production

The interpretation of the J/psi suppression patterns observed in nuclear collisions, at CERN and RHIC, as a signature of the formation of a deconfined phase of QCD matter, requires knowing which fractions of the measured J/psi yields, in pp collisions, are due to decays of heavier charmonium states. From a detailed analysis of the available mid-rapidity charmonium hadro-production cross sections, or their ratios, we determine that the J/psi feed-down contributions from psi' and chi_c decays are, respectively, (8.1 +/- 0.3) % and (25 +/- 5) %. These proton-proton values are derived from global averages of the proton-nucleus measurements, assuming that the charmonium states are exponentially absorbed with the length of matter they traverse in the nuclear targets.Comment: 12 pages, 4 figures, 3 table

Open charm contribution to dilepton spectra produced in nuclear collisions at SPS energies

Measurements of open charm hadro-production from CERN and Fermilab experiments are reviewed, with particular emphasis on the absolute cross sections and on their A and sqrt(s) dependences. Differential pt and xf cross sections calculated with the Pythia event generator are found to be in reasonable agreement with recent data. The calculations are scaled to nucleus-nucleus collisions and the expected lepton pair yield is deduced. The charm contribution to the low mass dilepton continuum observed by the CERES experiment is found to be negligible. In particular, it is shown that the observed low mass dilepton excess in S-Au collisions cannot be explained by charm enhancement.Comment: 19 pages, 12 eps figures included. To be published in Z.Phys.

Joint Stiffness Influence on the First-Order Seismic Capacity of Dry-Joint Masonry Structures: Numerical DEM Investigations

Heritage masonry structures are often modelled as dry-jointed structures. On the one hand, it may correspond to the reality where the initial mortar was weak, missing, or has disappeared through time because of erosion and lixiviation. On the other hand, this modelling approach reduces complexity to the studied problem, both from an experimental and theoretical/numerical point of views, while being conservative. Still, for modelling purposes, in addition to the joint friction, numerical approaches require a specific elastic parameter, the dry-joint stiffness, which is often hard to estimate experimentally. This work numerically investigates the effect of the joint stiffness on the collapse of scaled-down tilting test experiments carried out on perforated dry-joint masonry shear walls. It is found that geometrical imperfections of bricks and the absence of vertical precompression load can lead to very low equivalent dry-joint stiffness, which strongly affects the results, both in terms of collapse and damage limit state (DLS) loads, with practical implications for the engineering practice

Identificação, caracterização e inserção no mercado de produtos orgânicos na região da Barreira do Andirá.

A pesquisa objetivou caracterizar as principais cadeias de produtos orgânicos da agricultura familiar e sua inserção no mercado. Foi realizada na comunidade Barreira do Andirá, município de Barreirinha - AM e poderá vir a subsidiar propostas de desenvolvimento local sustentável. Como ferramenta de pesquisa utilizou-se o método estudo de caso. Identificando-se duas importantes cadeias produtivas: a da mandioca e a do guaraná e, a importância da organização social para alcançar o desenvolvimento rural com base na agroecologia

Proceedings of RIKEN BNL Research Center Workshop: Brookhaven Summer Program on Quarkonium Production in Elementary and Heavy Ion Collisions

Understanding the structure of the hadron is of fundamental importance in subatomic physics. Production of heavy quarkonia is arguably one of the most fascinating subjects in strong interaction physics. It offers unique perspectives into the formation of QCD bound states. Heavy quarkonia are among the most studied particles both theoretically and experimentally. They have been, and continue to be, the focus of measurements in all high energy colliders around the world. Because of their distinct multiple mass scales, heavy quarkonia were suggested as a probe of the hot quark-gluon matter produced in heavy-ion collisions; and their production has been one of the main subjects of the experimental heavy-ion programs at the SPS and RHIC. However, since the discovery of J/psi at Brookhaven National Laboratory and SLAC National Accelerator Laboratory over 36 years ago, theorists still have not been able to fully understand the production mechanism of heavy quarkonia, although major progresses have been made in recent years. With this in mind, a two-week program on quarkonium production was organized at BNL on June 6-17, 2011. Many new experimental data from LHC and from RHIC were presented during the program, including results from the LHC heavy ion run. To analyze and correctly interpret these measurements, and in order to quantify properties of the hot matter produced in heavy-ion collisions, it is necessary to improve our theoretical understanding of quarkonium production. Therefore, a wide range of theoretical aspects on the production mechanism in the vacuum as well as in cold nuclear and hot quark-gluon medium were discussed during the program from the controlled calculations in QCD and its effective theories such as NRQCD to various models, and to the first principle lattice calculation. The scientific program was divided into three major scientific parts: basic production mechanism for heavy quarkonium in vacuum or in high energy elementary collisions; the formation of quarkonium in nuclear medium as well as the strong interacting quark-gluon matter produced in heavy ion collisions; and heavy quarkonium properties from the first principle lattice calculations. The heavy quarkonium production at a future Electron-Ion Collider (EIC) was also discussed at the meeting. The highlight of the meeting was the apparent success of the NRQCD approach at next-to-leading order in the description of the quarkonium production in proton-proton, electron-proton and electron positron collisions. Still many questions remain open in lattice calculations of in-medium quarkonium properties and in the area of cold nuclear matter effects

Avaliação da produção de biomassa vegetal de quatro espécies visando a melhoria do solo de vegetação secundária na Amazônia Central.

Buscando técnicas inovadoras e sustentáveis para serem usadas na agricultura como forma de deixar o solo mais fértil e recuperar áreas modificadas, o presente trabalho foi realizado. No período de janeiro de 2011 a março de 2012, foram inseridas e monitoradas junto à capoeira no Campo Experimental da Embrapa Amazônia Ocidental km 29, quatro espécies vegetais conhecidas da Amazônia, (Tefrosia candida, Flemingia macrophyla, Bixa orellana e Inga edulis), tais espécies apresentam um grande potencial de acúmulo de biomassa e nutrientes

Levantamento e análise de resíduos biodegradáveis destinados a compostagem, originados em campo experimental.

A compostagem é uma pratica usada para o reaproveitamento de resíduos biodegradáveis na adubação orgânica, contribuindo com alguns nutrientes importantes para enriquecimento de solo, e ainda melhorando as condições estruturais do solo. Este trabalho teve como objetivo montar um banco de dados para qualificar os tipos de resíduos biodegradáveis originados nos campos experimentais. O estudo foi desenvolvido nos campos experimentais da Embrapa Amazônia Ocidental, o do KM 30 na rodovia AM 010 em Manaus e o do Caldeirão, no município de Iranduba

Perfil das unidades de produção familiares na comunidade de N. S. do Rosário - Parintins/AM.

O objetivo deste trabalho foi realizar a caracterização e a sistematização das práticas agrícolas sustentáveis desenvolvidas pelos agricultores familiares de comunidade tradicionais da Amazônia, devido o baixo interesse sobre estudos para a sistematização e caracterização de agriculturas com base ecológica nas comunidades rurais de terra firme no município foi escolhida uma comunidade com estas características