65 research outputs found

    The Physics of the B Factories

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    This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C

    Analysis on the Issue of East Financial Integration

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    在1997年金融危机发生后,东亚各国和地区意识到过分依赖外国的资金存在着巨大的风险。因此,为了避免对外国资金的过分依赖防止危机再次发生,东亚各国和地区通过完善金融体系,加强金融合作以推进金融一体化。 在此背景下,本文对东亚金融的一体化程度做出分析。本文对东亚各国和地区金融一体化的必要前提:东亚货币金融合作,东亚各国和地区资本市场放松管制情况、各国和地区的资本流动以及各国和地区股票及债券市场的发展进行了定性分析和描述,同时对各国投资与储蓄的相关性、各国消费者通过金融市场分散风险的程度、各国股票市场以及各国债券市场与两大国际市场间的联系,对东亚各国和地区金融市场一体化程度进行了实证分析。本文的研...East Asia has realized that it has great risk to depend on the foreign capital, after 1997 financial crisis. East Asia tried to improve the financial system and strengthen financial cooperation, so as to avoid the recurrence of financial crisis. This thesis tries to address the issue of the financial integration of East Asia. First of all, the basis of financial integration of East Asia was anal...学位:经济学博士院系专业:经济学院国际贸易系_世界经济学号:2005140292

    Towards theory-led evaluation: the experience of European science, technology, and innovation policies

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    This article reviews the literature and practice concerned with the evaluation of science, technology, and innovation (STI) policies and theway these relate to theories of the innovation process. Referring to the experience of the European Union (EU), the authors review the attempts to ensure that the STI policy theory is informed by advances in the authors'understanding of the innovation process. They argue, however, that the practice of policy evaluation lags behind advances in innovation theory. Despite the efforts to promote theory-led evaluations of STI policies based on new theories of the systemic nature of innovation, evaluation practice in the EU continues to favor the development of methods implicitly based on outdated linear views of the innovation process. This article examines the reasons why this is the case and suggests that STI policy evaluation should nevertheless be supported by the evolving theoretical understanding of the innovation process

    OBSERVATION OF SHORT-RANGE 3-PARTICLE CORRELATIONS IN E(+)E(-) ANNIHILATIONS AT LEP ENERGIES

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    Measurements are presented of short range three-particle correlations in e(+)e(-) annihilations at LEP using data collected by the DELPHI detector. At small values of the four-momentum difference, strong three-particle correlations are observed for like-sign (+++ and —) and for unlike-sign (++- and +–) pion combinations which are not a consequence of two-particle correlations. A possible explanation of the observed effects in like-sign combinations is the existence of higher order Bose-Einstein interference, which significantly changes the particle distributions in jets

    INCLUSIVE MEASUREMENTS OF THE K+/- AND P/(P)OVER-BAR PRODUCTION IN HADRONIC Z(0) DECAYS

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    This analysis, based on a sample of 170000 hadronic Z(0) decays, provides a measurement of the K-+/- and p/()overbarpdifferentialcrosssectionswhichiscomparedtostringandclusterfragmentationmodels.ThetotalmultiplicitiesforK+/andpipperhadroniceventwerefoundtobe:NK=2.26+/0.18andNp=1.07+/0.14.Thepositionsxiofthemaximaofthedifferentialcrosssectionsasafunctionofxi=In(1/x(p))forK+/andp/() over bar p differential cross sections which is compared to string- and cluster fragmentation models. The total multiplicities for K-+/- and pip per hadronic event were found to be: N-K = 2.26 +/- 0.18 and N-p = 1.07 +/- 0.14. The positions xi* of the maxima of the differential cross sections as a function of xi = In(1/x(p)) for K-+/- and p/() over bar p were determined to be 2.63 +/- 0.07 and 2.96 +/- 0.16 respectively. A comparison of the xi* values for various identified particles measured at LEP with the prediction of the Modified Leading Logarithm Approximation with Local Parton Hadron Duality model has been performed. The measured xi* position as a function of the hadron mass, after corrections due to particle decays, is in agreement with the model calculation

    A precise measurement of the tau lepton lifetime

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    The tau lepton lifetime has been measured using three different methods with the DELPHI detector. Two measurements of one-prong decays are combined, accounting for correlations, giving a result of tau(tau) = 291.8 +/- 3.3 (stat.) +/- 2.0(sys.) fs while the decay length distribution of three-prong decays gives the result tau(tau) = 286.7 +/- 4.9 (stat.) +/- 3.3 (sys.) fs. Combining the results presented here with previous DELPHI measurements, we get tau(tau) = 291.4 +/- 3.0 fs and find that the ratio of the coupling constant for tau decay relative to that for muon decay is 0.990 +/- 0.009, compatible with lepton universality

    MEASUREMENT OF TIME-DEPENDENT B-D(0) (B)OVER-BAR-D(0) MIXING

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    The time dependent mixing of B-d(0)-(B) over bar(d)(0) mesons has been observed by using the correlations between the charge of D-* mesons and the weighted mean charge of particles in each hemisphere. From a reconstructed D-*+/- sample corresponding to about 1.7 million hadronic Z(0) decays, the mass difference between the two B-d(0) mass eigenstates has been measured to be hm = 0.50 +/- 0.12 (stat.) +/- 0.06 (syst.) (h) over bar/ps or, converting into eV/c(2): Delta m = [3.29 +/- 0.79 (stat.) +/- 0.39 (syst.)] 10(-4) eV/c(2)

    FIRST EVIDENCE OF HARD SCATTERING PROCESSES IN SINGLE TAGGED GAMMA-GAMMA-COLLISIONS

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    For the first time, multihadronic production from single tagged gamma gamma collisions has been studied, where one of the scattered leptons was tagged at very low virtual photon absolute mass squared ([Q(2)] = 0.06 (GeV/c(2))(2)). Data collected during 1991 and 1992 in the DELPHI experiment at LEP are shown to agree well with predictions which included the non-perturbative vector meson dominance model in which the interacting photons are assumed to have converted into a vector meson (rho, omega or pi), a quark-parton model which describes direct photon interactions and a QCD-based model which considers the photon to have quark and gluon structure functions. Five different parametrizations of these structure functions were used and the predictions compared with the data. This study confirms recent results from no-tag experiments in requiring a QCD-based component to successfully describe the data, indicating that the photon has a significant partonic content
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