84 research outputs found

    A Simultaneous Measurement of the Branching Fractions of Ten B to Double Charm Decays

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    This dissertation presents a simultaneous measurement of the branching fractions of ten B → D(*)D̅(*) decays. The measurements are derived from a sample of 2.32 × 108 BB̅ pairs collected by the BABAR detector at the PEP-ⅡB Factory located at Stanford Linear Accelerator Center. The branching fractions (×10−4) are:      −0.10 ± 0.47 ± 0.15 (< 0.59) for B0 → D0D̅0      1.01 ± 1.11 ± 0.35 (< 2.92) for B0 → D*0D̅0      −1.31 ± 1.10 ± 0.38 (< 0.92) for B0 → D*0D̅*0      2.81 ± 0.44 ± 0.45 for B0 → D+D−      5.72 ± 0.65 ± 0.71 for B0 → D*+D−      8.11 ± 0.57 ± 0.98 for B0 → D*+D*−      3.76 ± 0.59 ± 0.45 for B− → D−D0      3.56 ± 0.54 ± 0.40 for B− → D*−D0      6.30 ± 1.35 ± 0.95 for B− → D−D*0      8.14 ± 1.20 ± 1.16 for B− → D*−D*0 The first uncertainty is statistical while the second is systematic. The number in parentheses is the 90% upper limit using the Feldman-Cousins method with systematic uncertainties taken into account. These measurements are consistent with the Standard Model predictions using the factorization assumption

    stairs and fire

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    Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

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    A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació

    Track Reconstruction with Cosmic Ray Data at the Tracker Integration Facility

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    The subsystems of the CMS silicon strip tracker were integrated and commissioned at the Tracker Integration Facility (TIF) in the period from November 2006 to July 2007. As part of the commissioning, large samples of cosmic ray data were recorded under various running conditions in the absence of a magnetic field. Cosmic rays detected by scintillation counters were used to trigger the readout of up to 15\,\% of the final silicon strip detector, and over 4.7~million events were recorded. This document describes the cosmic track reconstruction and presents results on the performance of track and hit reconstruction as from dedicated analyses

    Transverse momentum and pseudorapidity distributions of charged hadrons in pp collisions at (s)\sqrt(s) = 0.9 and 2.36 TeV

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    Measurements of inclusive charged-hadron transverse-momentum and pseudorapidity distributions are presented for proton-proton collisions at sqrt(s) = 0.9 and 2.36 TeV. The data were collected with the CMS detector during the LHC commissioning in December 2009. For non-single-diffractive interactions, the average charged-hadron transverse momentum is measured to be 0.46 +/- 0.01 (stat.) +/- 0.01 (syst.) GeV/c at 0.9 TeV and 0.50 +/- 0.01 (stat.) +/- 0.01 (syst.) GeV/c at 2.36 TeV, for pseudorapidities between -2.4 and +2.4. At these energies, the measured pseudorapidity densities in the central region, dN(charged)/d(eta) for |eta| < 0.5, are 3.48 +/- 0.02 (stat.) +/- 0.13 (syst.) and 4.47 +/- 0.04 (stat.) +/- 0.16 (syst.), respectively. The results at 0.9 TeV are in agreement with previous measurements and confirm the expectation of near equal hadron production in p-pbar and pp collisions. The results at 2.36 TeV represent the highest-energy measurements at a particle collider to date
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