386 research outputs found

    OspA heterogeneity of Borrelia valaisiana confirmed by phenotypic and genotypic analyses

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    BACKGROUND: Although European Borrelia burgdorferi sensu lato isolates have been divided into five genospecies, specific tools for the serotype characterization of only three genospecies are available. Monoclonals antibodies (mAbs) H3TS, D6 and I17.3 identify B. burgdorferi sensu stricto (ss.), B. garinii and B. afzelii respectively, but no mAbs are available to identify B. valaisiana. In the same way, specific primers exist to amplify the OspA gene of B. burgdorferi ss., B. garinii and B. afzelii. The aim of the study was to develop species-specific mAb and PCR primers for the phenotypic and genetic identification of B. valaisiana. RESULTS: This study describes a mAb that targets OspA of B. valaisiana and primers targeting the OspA gene of this species. As the monoclonal antibody A116k did not react with strains NE231, M7, M53 and Frank and no amplification was observed with strains NE231, M7 and M53, the existence of two subgroups among European B. valaisiana species was confirmed. CONCLUSIONS: The association of both monoclonal antibody A116k and primers Bval 1F and Bval 1R allows to specific identification of the B. valaisiana isolates belonging to subgroup 1

    Measurement of a small atmospheric νμ/νe\nu_\mu/\nu_e ratio

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    From an exposure of 25.5~kiloton-years of the Super-Kamiokande detector, 900 muon-like and 983 electron-like single-ring atmospheric neutrino interactions were detected with momentum pe>100p_e > 100 MeV/cc, pμ>200p_\mu > 200 MeV/cc, and with visible energy less than 1.33 GeV. Using a detailed Monte Carlo simulation, the ratio (μ/e)DATA/(μ/e)MC(\mu/e)_{DATA}/(\mu/e)_{MC} was measured to be 0.61±0.03(stat.)±0.05(sys.)0.61 \pm 0.03(stat.) \pm 0.05(sys.), consistent with previous results from the Kamiokande, IMB and Soudan-2 experiments, and smaller than expected from theoretical models of atmospheric neutrino production.Comment: 14 pages with 5 figure

    Evidence for B0->pi0pi0

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    We report evidence for the decay B0->pi0pi0. The analysis is based on a data sample of 152million BBbar pairs collected at the Upsilon(4s) resonance with the Belle detector at the KEKB e+e- storage ring. We find 25.6+9.3/-8.4(stat)+1.6/-1.4(syst) B0->pi0pi0 signal events with a significance of 3.4 standard deviations. We measure the branching fraction to be (1.7+-0.6(stat)+-0.2(syst))*10^{-6}.Comment: Submitted to PR

    Observation of BK+B \to K^* \ell^+ \ell^-

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    We report the first observation of the flavor-changing neutral current decay BK+B \to K^* \ell^+ \ell^- and an improved measurement of the decay BK+B \to K \ell^+ \ell^-, where \ell represents an electron or a muon, with a data sample of 140 fb1{}^{-1} accumulated at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at KEKB. The results for the branching fractions are B(BK+)=(11.52.4+2.6±0.8±0.2)×107{\cal B}(B \to K^* \ell^+ \ell^-)=(11.5^{+2.6}_{-2.4} \pm 0.8 \pm 0.2) \times 10^{-7} and B(BK+)=(4.80.9+1.0±0.3±0.1)×107{\cal B}(B \to K \ell^+ \ell^-)=(4.8^{+1.0}_{-0.9} \pm 0.3 \pm 0.1) \times 10^{-7}, where the first error is statistical, the second is systematic and the third is from model dependence.Comment: 11 pages, 2 figures, submitted to PR

    Observation of the DsJ(2317) and DsJ(2457) in B decays

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    We report the first observation of the B --> Dbar DsJ(2317) and B --> Dbar DsJ(2457) decays based on 123.8 10^6 BBar events collected with the Belle detector at KEKB. We observe the DsJ(2317) decay to Ds pi0 and DsJ(2457) decay to the Ds* pi0 and Ds gamma final states. We also set 90% CL upper limits for the decays DsJ(2317) --> Ds* gamma, DsJ(2457) --> Ds* gamma, DsJ(2457) --> Ds pi0 and DsJ(2457) --> Ds pi+ pi-.Comment: 6 pages, 3 figures. A few minor corrections. Replaced by version accepted to publication in Phys. Rev. Let

    Measurements of the DsJD_{sJ} resonance properties

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    We report measurements of the properties of the DsJ+(2317)D_{sJ}^+(2317) and DsJ+(2457)D_{sJ}^+(2457) resonances produced in continuum e+ee^+ e^- annihilation near s=10.6GeV\sqrt{s}=10.6 \mathrm{GeV}. The analysis is based on an 86.9fb186.9 \mathrm{fb^{-1}} data sample collected %at and 60 MeV below the Υ(4S)\Upsilon(4S) resonance with with the Belle detector at KEKB. We determine the masses to be M(DsJ+(2317))=2317.2±0.5(stat)±0.9(syst)MeV/c2M(D_{sJ}^+(2317)) = 2317.2 \pm 0.5(\mathrm{stat}) \pm 0.9(\mathrm{syst}) \mathrm{MeV}/c^2 and M(DsJ+(2457))=2456.5±1.3(stat)±1.3(syst)MeV/c2M(D_{sJ}^+(2457))=2456.5 \pm 1.3(\mathrm{stat}) \pm 1.3(\mathrm{syst}) \mathrm{MeV}/c^2. We observe the radiative decay mode DsJ+(2457)Ds+γD_{sJ}^+(2457) \to D_s^+ \gamma and the dipion decay mode DsJ+(2457)Ds+π+πD_{sJ}^+(2457) \to D_s^+ \pi^+ \pi^-, and determine their branching fractions. No corresponding decays are observed for the DsJ(2317)D_{sJ}(2317) state. These results are consistent with the spin-parity assignments of 0+0^+ for the DsJ(2317)D_{sJ}(2317) and 1+1^+ for the DsJ(2457)D_{sJ}(2457).Comment: 5 pages, 6 figures; Added content, updated and paper submitted to PR

    Evidence for Direct CP Violation in B0 -> K+- pi-+ Decays

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    We report evidence for direct CP violation in the decay B0 -> K+-pi-+ with 253/fb of data collected with the Belle detector at the KEKB e+e- collider. Using 275 million B B_bar pairs we observe a B -> K+-pi-+ signal with 2140+-53 events. The measured CP violating asymmetry is Acp(K+-pi-+) = -0.101+-0.025 (stat)+-0.005 (syst), corresponding to a significance of 3.9 sigma including systematics. We also search for CP violation in the decays B+- -> K+-pi0 and B+- -> pi+-pi0. The measured CP violating asymmetries are Acp(K+-pi0) = 0.04+-0.05(stat)+-0.02(syst) and Acp(pi+-pi0) = -0.02+-0.10(stat)+-0.01(syst), corresponding to the intervals -0.05 < Acp(K+-pi0) < 0.13 and -0.18<Acp(pi+-pi0)<0.14 at 90% confidence level.Comment: 9 pages, 3 figures. submitted to Physical Review Letter

    Measurement of Time-Dependent CP-Violating Asymmetries in B0 --> phi Ks0, K+ K- Ks0, and eta' Ks0 Decays

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    We present an improved measurement of CP-violation parameters in B0 --> phi Ks0, K+ K- Ks0, and eta' Ks0 decays based on a 140 fb-1 data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. One neutral B meson is fully reconstructed in one of the specified decay channels, and the flavor of the accompanying B meson is identified from its decay products. CP-violation parameters for each of the three modes are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays. We find that the observed CP asymmetry in the B0 --> phi Ks0 decay differs from the standard model (SM) expectation by 3.5 standard deviations, while the other cases are consistent with the SM.Comment: 10 pages, 4 postscript figures, submitted to Physical Review Letters, also contributed to the XXI International Symposium on Lepton and Photon Interactions at High Energies, Aug 11-16, 2003, Fermilab, Illinois US

    Belle II Technical Design Report

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    The Belle detector at the KEKB electron-positron collider has collected almost 1 billion Y(4S) events in its decade of operation. Super-KEKB, an upgrade of KEKB is under construction, to increase the luminosity by two orders of magnitude during a three-year shutdown, with an ultimate goal of 8E35 /cm^2 /s luminosity. To exploit the increased luminosity, an upgrade of the Belle detector has been proposed. A new international collaboration Belle-II, is being formed. The Technical Design Report presents physics motivation, basic methods of the accelerator upgrade, as well as key improvements of the detector.Comment: Edited by: Z. Dole\v{z}al and S. Un
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