1,526 research outputs found

    Mongolian and Japanese Joint Conference on "Echinococcosis: diagnosis, treatment and prevention in Mongolia" June 4, 2009

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    The first Mongolian-Japanese Joint Conference on "Echinococcosis: diagnosis, treatment and prevention in Mongolia" was held in Ulaanbaatar on June 4th, 2009. It was the first chance for Mongolian experts (clinicians, pathologists, parasitologists, biologists, epidemiologists, veterinarians and others working on echinococcosis) joined together. Increase in the number of cystic echinococcosis (CE) cases year by year was stressed. CE in children may be more than adult cases. Alveolar echinococcosis was suspected chronic malignant hepatic tumors or abscesses. Main discussion was as to how to introduce modern diagnostic tools for pre-surgical diagnosis, how to establish the national system for the data base of echinococcosis with the establishment of a network system by experts from different areas. The importance of molecular identification of the parasites in domestic and wild animals was also stressed

    Measurement of the Bs0J/ψηB_{s}^{0} \rightarrow J/\psi \eta lifetime

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    Using a data set corresponding to an integrated luminosity of 3fb13 fb^{-1}, collected by the LHCb experiment in pppp collisions at centre-of-mass energies of 7 and 8 TeV, the effective lifetime in the Bs0J/ψηB^0_s \rightarrow J/\psi \eta decay mode, τeff\tau_{\textrm{eff}}, is measured to be τeff=1.479±0.034 (stat)±0.011 (syst)\tau_{\textrm{eff}} = 1.479 \pm 0.034~\textrm{(stat)} \pm 0.011 ~\textrm{(syst)} ps. Assuming CPCP conservation, τeff\tau_{\textrm{eff}} corresponds to the lifetime of the light Bs0B_s^0 mass eigenstate. This is the first measurement of the effective lifetime in this decay mode.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-2016-017.htm

    Observation of an Excited Bc+ State

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    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+γ 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

    Model-independent evidence for J/ψpJ/\psi p contributions to Λb0J/ψpK\Lambda_b^0\to J/\psi p K^- decays

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    The data sample of Λb0J/ψpK\Lambda_b^0\to J/\psi p K^- decays acquired with the LHCb detector from 7 and 8~TeV pppp collisions, corresponding to an integrated luminosity of 3 fb1^{-1}, is inspected for the presence of J/ψpJ/\psi p or J/ψKJ/\psi K^- contributions with minimal assumptions about KpK^- p contributions. It is demonstrated at more than 9 standard deviations that Λb0J/ψpK\Lambda_b^0\to J/\psi p K^- decays cannot be described with KpK^- p contributions alone, and that J/ψpJ/\psi p contributions play a dominant role in this incompatibility. These model-independent results support the previously obtained model-dependent evidence for Pc+J/ψpP_c^+\to J/\psi p charmonium-pentaquark states in the same data sample.Comment: 21 pages, 12 figures (including the supplemental section added at the end

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

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    A study of Bc+K+Kπ+B_c^+\to K^+K^-\pi^+ decays is performed for the first time using data corresponding to an integrated luminosity of 3.0 fb1\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 (9.83.0+3.4(stat)±0.8(syst))×106(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(Kπ+)<1.834GeV ⁣/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

    Study of J /ψ production in Jets

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    The production of J/ψ mesons in jets is studied in the forward region of proton-proton collisions using data collected with the LHCb detector at a center-of-mass energy of 13 TeV. The fraction of the jet transverse momentum carried by the J/ψ meson, z(J/ψ)≡pT(J/ψ)/pT(jet), is measured using jets with pT(jet)>20 GeV in the pseudorapidity range 2.5<η(jet)<4.0. The observed z(J/ψ)distribution for J/ψ mesons produced in b-hadron decays is consistent with expectations. However, the results for prompt J/ψ production do not agree with predictions based on fixed-order nonrelativistic QCD. This is the first measurement of the pT fraction carried by prompt J/ψ mesons in jets at any experiment

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

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    The first full amplitude analysis of B+J/ψϕK+B^+\to J/\psi \phi K^+ with J/ψμ+μJ/\psi\to\mu^+\mu^-, ϕK+K\phi\to K^+K^- decays is performed with a data sample of 3 fb1^{-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

    Observation of J/ψϕJ/\psi\phi structures consistent with exotic states from amplitude analysis of B+J/ψϕK+B^+\to J/\psi \phi K^+ decays

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    The first full amplitude analysis of B+J/ψϕK+B^+\to J/\psi \phi K^+ with J/ψμ+μJ/\psi\to\mu^+\mu^-, ϕK+K\phi\to K^+K^- decays is performed with a data sample of 3 fb1^{-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.Comment: 17 pages, 3 figure
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