578 research outputs found

    Farinha mista de mandioca com castanha-do-brasil: uma alternativa agroecolĂłgica para a Reserva Extrativista CazumbĂĄ-Iracema.

    Get PDF
    A farinha de mandioca Ă© o principal produto em importĂąncia alimentar servindo como fonte de energia e geração de renda para os agricultores familiares da AmazĂŽnia. A castanha-do-brasil Ă© uma das principais fontes de proteĂ­na vegetal, geração de emprego e renda para os extrativistas da AmazĂŽnia. Este trabalho teve como objetivo analisar o arranjo produtivo local da farinha mista de mandioca com castanha-do-brasil e a produtividade de mandioca em ĂĄrea de agricultores familiares na Reserva Extrativista CazumbĂĄ-Iracema, Sena Madureira-AC. Foram avaliados os critĂ©rios de dimensĂ”es econĂŽmicas, agronĂŽmicas, ambientais e sociais destes arranjos produtivos locais. O potencial produtivo da mandioca e da castanha foram avaliados atravĂ©s de ensaios de campo e entrevistas tĂ©cnicas junto Ă s famĂ­lias dos agricultores e extrativistas das comunidades Cuidado, NĂșcleo CazumbĂĄ e Alto CaetĂ©. O resultado desta anĂĄlise indica que existe grande potencial de desenvolvimento social e econĂŽmico de toda a RESEX, com geração e distribuição de renda

    Observation of J/ψpJ/\psi p resonances consistent with pentaquark states in Λb0→J/ψK−p{\Lambda_b^0\to J/\psi K^-p} decays

    Get PDF
    Observations of exotic structures in the J/ψpJ/\psi p channel, that we refer to as pentaquark-charmonium states, in Λb0→J/ψK−p\Lambda_b^0\to J/\psi K^- p decays are presented. The data sample corresponds to an integrated luminosity of 3/fb acquired with the LHCb detector from 7 and 8 TeV pp collisions. An amplitude analysis is performed on the three-body final-state that reproduces the two-body mass and angular distributions. To obtain a satisfactory fit of the structures seen in the J/ψpJ/\psi p mass spectrum, it is necessary to include two Breit-Wigner amplitudes that each describe a resonant state. The significance of each of these resonances is more than 9 standard deviations. One has a mass of 4380±8±294380\pm 8\pm 29 MeV and a width of 205±18±86205\pm 18\pm 86 MeV, while the second is narrower, with a mass of 4449.8±1.7±2.54449.8\pm 1.7\pm 2.5 MeV and a width of 39±5±1939\pm 5\pm 19 MeV. The preferred JPJ^P assignments are of opposite parity, with one state having spin 3/2 and the other 5/2.Comment: 48 pages, 18 figures including the supplementary material, v2 after referee's comments, now 19 figure

    Observation of the Bs0→J/ψϕϕB_s^0 \rightarrow J/\psi \phi \phi decay

    Get PDF
    The Bs0→J/ψϕϕB_s^0 \rightarrow J/\psi \phi \phi decay is observed in pppp collision data corresponding to an integrated luminosity of 3 fb−1^{-1} recorded by the LHCb detector at centre-of-mass energies of 7 TeV and 8 TeV. This is the first observation of this decay channel, with a statistical significance of 15 standard deviations. The mass of the Bs0B_s^0 meson is measured to be 5367.08 ± 0.38 ± 0.155367.08\,\pm \,0.38\,\pm\, 0.15 MeV/c2^2. The branching fraction ratio B(Bs0→J/ψϕϕ)/B(Bs0→J/ψϕ)\mathcal{B}(B_s^0 \rightarrow J/\psi \phi \phi)/\mathcal{B}(B_s^0 \rightarrow J/\psi \phi) is measured to be 0.0115\,\pm\, 0.0012\, ^{+0.0005}_{-0.0009}. In both cases, the first uncertainty is statistical and the second is systematic. No evidence for non-resonant Bs0→J/ψϕK+K−B_s^0 \rightarrow J/\psi \phi K^+ K^- or Bs0→J/ψK+K−K+K−B_s^0 \rightarrow J/\psi K^+ K^- K^+ K^- decays is found.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-033.htm

    Precise measurements of the properties of the B-1(5721)(0,+) and B-2*(5747)(0,+) states and observation of B-+,B-0 pi(-,+) mass structures

    Get PDF
    Invariant mass distributions of B+π− and B0π+ combinations are investigated in order to study excited B mesons. The analysis is based on a data sample corresponding to 3.0 fb−1 of pp collision data, recorded by the LHCb detector at centre-of-mass energies of 7 and 8 TeV. Precise measurements of the masses and widths of the B1(5721)0,+ and B2(5747)0,+ states are reported. Clear enhancements, particularly prominent at high pion transverse momentum, are seen over background in the mass range 5850-6000 MeV in both B+π− and B0π+ combinations. The structures are consistent with the presence of four excited B mesons, labelled BJ (5840)0,+ and BJ (5960)0,+, whose masses and widths are obtained under different hypotheses for their quantum numbers

    Observation of an Excited Bc+ State

    Get PDF
    Using pp collision data corresponding to an integrated luminosity of 8.5 fb-1 recorded by the LHCb experiment at center-of-mass energies of s=7, 8, and 13 TeV, the observation of an excited Bc+ state in the Bc+π+π- invariant-mass spectrum is reported. The observed peak has a mass of 6841.2±0.6(stat)±0.1(syst)±0.8(Bc+) MeV/c2, where the last uncertainty is due to the limited knowledge of the Bc+ mass. It is consistent with expectations of the Bc∗(2S31)+ state reconstructed without the low-energy photon from the Bc∗(1S31)+→Bc+Îł decay following Bc∗(2S31)+→Bc∗(1S31)+π+π-. A second state is seen with a global (local) statistical significance of 2.2σ (3.2σ) and a mass of 6872.1±1.3(stat)±0.1(syst)±0.8(Bc+) MeV/c2, and is consistent with the Bc(2S10)+ state. These mass measurements are the most precise to date

    Amplitude analysis of B+→J/ψϕK+B^+\to J/\psi \phi K^+ decays

    Get PDF
    The first full amplitude analysis of B+→J/ψϕK+B^+\to J/\psi \phi K^+ with J/ψ→Ό+Ό−J/\psi\to\mu^+\mu^-, ϕ→K+K−\phi\to K^+K^- decays is performed with a data sample of 3 fb−1^{-1} of pppp collision data collected at s=7\sqrt{s}=7 and 88 TeV with the LHCb detector. The data cannot be described by a model that contains only excited kaon states decaying into ϕK+\phi K^+, and four J/ψϕJ/\psi\phi structures are observed, each with significance over 55 standard deviations. The quantum numbers of these structures are determined with significance of at least 44 standard deviations. The lightest has mass consistent with, but width much larger than, previous measurements of the claimed X(4140)X(4140) state. The model includes significant contributions from a number of expected kaon excitations, including the first observation of the K∗(1680)+→ϕK+K^{*}(1680)^+\to\phi K^+ transition.Comment: 62 pages 26 figure

    Study of Bc+B_c^+ decays to the K+K−π+K^+K^-\pi^+ final state and evidence for the decay Bc+→χc0π+B_c^+\to\chi_{c0}\pi^+

    Get PDF
    A study of Bc+→K+K−π+B_c^+\to K^+K^-\pi^+ decays is performed for the first time using data corresponding to an integrated luminosity of 3.0 fb−1\mathrm{fb}^{-1} collected by the LHCb experiment in pppp collisions at centre-of-mass energies of 77 and 88 TeV. Evidence for the decay Bc+→χc0(→K+K−)π+B_c^+\to\chi_{c0}(\to K^+K^-)\pi^+ is reported with a significance of 4.0 standard deviations, resulting in the measurement of σ(Bc+)σ(B+)×B(Bc+→χc0π+)\frac{\sigma(B_c^+)}{\sigma(B^+)}\times\mathcal{B}(B_c^+\to\chi_{c0}\pi^+) to be (9.8−3.0+3.4(stat)±0.8(syst))×10−6(9.8^{+3.4}_{-3.0}(\mathrm{stat})\pm 0.8(\mathrm{syst}))\times 10^{-6}. Here B\mathcal{B} denotes a branching fraction while σ(Bc+)\sigma(B_c^+) and σ(B+)\sigma(B^+) are the production cross-sections for Bc+B_c^+ and B+B^+ mesons. An indication of bˉc\bar b c weak annihilation is found for the region m(K−π+)<1.834 GeV ⁣/c2m(K^-\pi^+)<1.834\mathrm{\,Ge\kern -0.1em V\!/}c^2, with a significance of 2.4 standard deviations.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-022.html, link to supplemental material inserted in the reference

    Peripheral Nervous System Genes Expressed in Central Neurons Induce Growth on Inhibitory Substrates

    Get PDF
    Trauma to the spinal cord and brain can result in irreparable loss of function. This failure of recovery is in part due to inhibition of axon regeneration by myelin and chondroitin sulfate proteoglycans (CSPGs). Peripheral nervous system (PNS) neurons exhibit increased regenerative ability compared to central nervous system neurons, even in the presence of inhibitory environments. Previously, we identified over a thousand genes differentially expressed in PNS neurons relative to CNS neurons. These genes represent intrinsic differences that may account for the PNS’s enhanced regenerative ability. Cerebellar neurons were transfected with cDNAs for each of these PNS genes to assess their ability to enhance neurite growth on inhibitory (CSPG) or permissive (laminin) substrates. Using high content analysis, we evaluated the phenotypic profile of each neuron to extract meaningful data for over 1100 genes. Several known growth associated proteins potentiated neurite growth on laminin. Most interestingly, novel genes were identified that promoted neurite growth on CSPGs (GPX3, EIF2B5, RBMX). Bioinformatic approaches also uncovered a number of novel gene families that altered neurite growth of CNS neurons

    Measurement of the Z+b-jet cross-section in pp collisions at √s = 7 TeV in the forward region

    Get PDF
    The associated production of a Z boson or an off-shell photon Îł ∗ with a bottom quark in the forward region is studied using proton-proton collisions at a centre-of-mass energy of 7 TeV. The Z bosons are reconstructed in the Z/γ∗ → ” +” − final state from muons with a transverse momentum larger than 20 GeV, while two transverse momentum thresholds are considered for jets (10 GeV and 20 GeV). Both muons and jets are reconstructed in the pseudorapidity range 2.0 &#60; η &#60; 4.5. The results are based on data corresponding to 1.0 fb−1 recorded in 2011 with the LHCb detector. The measurement of the Z+b-jet cross-section is normalized to the Z+jet cross-section. The measured cross-sections are σ(Z/γ∗ (” +” −) + b-jet) = 295 ± 60 (stat) ± 51 (syst) ± 10 (lumi) fb (0.1) for pT(jet) &#62; 10 GeV, and σ(Z/γ∗ (” +” −) + b-jet) = 128 ± 36 (stat) ± 22 (syst) ± 5 (lumi) fb (0.2) for pT(jet) &#62; 20 GeV

    Observation of the B0 → ρ0ρ0 decay from an amplitude analysis of B0 → (π+π-)(π+π-) decays

    Get PDF
    Proton-proton collision data recorded in 2011 and 2012 by the LHCb experiment, corresponding to an integrated luminosity of 3.0 fb-1, are analysed to search for the charmless B0→ρ0ρ0 decay. More than 600 B0→(π+π-)(π+π-) signal decays are selected and used to perform an amplitude analysis, under the assumption of no CP violation in the decay, from which the B0→ρ0ρ0 decay is observed for the first time with 7.1 standard deviations significance. The fraction of B0→ρ0ρ0 decays yielding a longitudinally polarised final state is measured to be fL=0.745-0.058+0.048(stat)±0.034(syst). The B0→ρ0ρ0 branching fraction, using the B0→ϕK*(892)0 decay as reference, is also reported as B(B0→ρ0ρ0)=(0.94±0.17(stat)±0.09(syst)±0.06(BF))×10-6
    • 

    corecore