785 research outputs found

    Eine empirische Untersuchung von Kosteneinflußfaktoren bei integrationsorientierten Reengineering-Projekten

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    Die Zusammenhänge zwischen Merkmalen eines Software-Altsystems und den daraus resultierenden Kosten für bestimmte Reengineering-Aktivitäten sind nahezu unerforscht. Der vorliegende Arbeitsbericht schildert die experimentelle Untersuchung von drei ausgewählten Einflußfaktoren bei einer für das integrationsorientierte Reengineering typischen Aufgabenstellung. Untersucht wurden die Wirkungen der Komplexität des Quelltexts, der Dokumentiertheit der Datenstrukturen sowie der Verfügbarkeit von Tages- bzw. Testdaten

    Low scale B-L extension of the Standard Model at the LHC

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    The fact that neutrinos are massive indicates that the Standard Model (SM) requires extension. We propose a low energy (<TeV) B-L extension of the SM, which is based on the gauge group SU(3)_C x SU(2)_L x U(1)_Y x U(1)_{B-L}. We show that this model provides a natural explanation for the presence of three right-handed neutrinos in addition to an extra gauge boson and a new scalar Higgs. Therefore, it can lead to very interesting phenomenological implications different from the SM results which can be tested at the LHC. Also we analyze the muon anomalous magnetic moment in this class of models. We show that one-loop with exchange Z' may give dominant new contribution ~ few x 10^{-11}.Comment: 12 page

    Status of KLOE-2

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    In a few months the KLOE-2 detector is expected to start data taking at the upgraded DAΦ\rm{\Phi}NE ϕ\phi-factory of INFN Laboratori Nazionali di Frascati. It aims to collect 25 fb1^{-1} at the ϕ(1020)\phi(1020) peak, and about 5 fb1^{-1} in the energy region between 1 and 2.5 GeV. We review the status and physics program of the projectComment: 6 pages, 5 figures, to appear in the Proceedings of the PHIPSI09 Workshop, Oct 13-16, 2009, Beijing, Chin

    Light dark forces at flavor factories

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    SuperB experiment could represent an ideal environment to test a new U (1) symmetry related to light dark forces candidates. A promising discovery channel is represented by the resonant production of a boson U, followed by its decay into lepton pairs. Beyond approximations adopted in the literature, an exact tree level calculation of the radiative processes e+eγ,Uμ+μγ,e+eγe+ e- \rightarrow \gamma, U \rightarrow \mu^+ \mu^- \gamma, e^+ e^- \gamma and corresponding QED backgrounds is performed, including also the most important higher-order corrections. The calculation is implemented in a release of the generator BabaYaga@NLO useful for data analysis and interpretation. The distinct features of U boson production are shown and the statistical significance is analysed

    Transport properties of heterogeneous materials derived from Gaussian random fields: Bounds and Simulation

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    We investigate the effective conductivity (σe\sigma_e) of a class of amorphous media defined by the level-cut of a Gaussian random field. The three point solid-solid correlation function is derived and utilised in the evaluation of the Beran-Milton bounds. Simulations are used to calculate σe\sigma_e for a variety of fields and volume fractions at several different conductivity contrasts. Relatively large differences in σe\sigma_e are observed between the Gaussian media and the identical overlapping sphere model used previously as a `model' amorphous medium. In contrast σe\sigma_e shows little variability between different Gaussian media.Comment: 15 pages, 14 figure

    Hadronic light-by-light scattering contribution to the muon g-2

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    We review recent developments concerning the hadronic light-by-light scattering contribution to the anomalous magnetic moment of the muon. We first discuss why fully off-shell hadronic form factors should be used for the evaluation of this contribution to the g-2. We then reevaluate the numerically dominant pion-exchange contribution in the framework of large-N_C QCD, using an off-shell pion-photon-photon form factor which fulfills all QCD short-distance constraints, in particular, a new short-distance constraint on the off-shell form factor at the external vertex in g-2, which relates the form factor to the quark condensate magnetic susceptibility in QCD. Combined with available evaluations of the other contributions to hadronic light-by-light scattering this leads to the new result a_{\mu}(LbyL; had) = (116 \pm 40) x 10^{-11}, with a conservative error estimate in view of the many still unsolved problems. Some potential ways for further improvements are briefly discussed as well. For the electron we obtain the new estimate a_{e}(LbyL; had) = (3.9 \pm 1.3) x 10^{-14}.Comment: 6 pages, 1 figure, to be published in the proceedings of the PhiPsi09 workshop, Oct. 13-16, 2009, Beijing, Chin

    Constraining the Hadronic Contributions to the Muon Anomalous Magnetic Moment

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    The mini-proceedings of the Workshop on "Constraining the hadronic contributions to the muon anomalous magnetic moment" which included the "13th meeting of the Radio MonteCarLow WG" and the "Satellite meeting R-Measurements at BES-III" held in Trento from April 10th to 12th, 2013, are presented. This collaboration meeting aims to bring together the experimental e+e- collider communities from BaBar, Belle, BESIII, CMD2, KLOE, and SND, with theorists working in the fields of meson transitions form factors, hadronic contributions to (g-2)_\mu and effective fine structure constant, and development of Monte Carlo generator and Radiative Corrections for precision e+e- and tau physics.Comment: 45 pages, 17 contributions. Editors: P. Masjuan and G. Venanzon

    The Law of Society: Governance Through Contract

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    This paper focuses on contract law as a central field in contemporary regulatory practice. In recent years, governance by contract has emerged as the central concept in the context of domestic privatization, domestic and transnational commercial relations and law-and-development projects. Meanwhile, as a result of the neo-formalist attack on contract law, governance of contract through contract adjudication, consumer protection law and judicial intervention into private law relations has come under severe pressure. Building on early historical critique of the formalist foundations of an allegedly private law of the market, the paper assesses the current justifications for contractual governance and posits that only an expanded legal realist perspective can adequately explain the complex nature of contractual agreements in contemporary practice. The paper argues for an understanding of contracts as complex societal arrangements that visibilize and negotiate conflicting rationalities and interests. Institutionally, contractual governance has been unfolding in a complex, historically grown and ideologically continually contested regulatory field. Governance through contract, then, denotes a wide field of conflicting concepts, ideas and symbols, that are themselves deeply entrenched in theories of society, market and the state. From this perspective, we are well advised to study contracts in their socio-economic, historical and cultural context. A careful reading of scholars such as Henry Sumner Maine, Morris Cohen, Robert Hale, Karl Llewellyn, Stewart Macaulay and Ian Macneil offers a deeper understanding of the institutional and normative dimensions of contractual governance. Their analysis is particularly helpful in assessing currently ongoing shifts away from a welfare state based regulation (governance) of contractual relations. Such shifts are occurring on two levels. First, they take place against the backdrop of a neo-liberal critique of government interference into allegedly private relations. Secondly, the increasingly influential return to formalism in contract law, which privileges a functionalist, purportedly technical and autonomous design and execution of contractual agreements over the view of regulated contracts, is linked to a particular concept of sovereignty. The ensuing revival of freedom of contract occurs in remarkable neglect of the experiences of welfare state adjudication of private law adjudication and a continuing contestation of the political in private relationships. The paper takes up the Legal Realists\u27 search for the \u27basis of contract\u27, but seeks to redirect the focus from the traditional perspective on state vs. market to a disembedded understanding of contractual governance as delineating multipolar and multirational regulatory regimes. Where Globalization has led to a fragmentation, disembeddedness and transnationalization of contexts and, thus, has been challenging traditional understanding of embeddedness, the task should no longer be to try applying a largely nation-state oriented Legal Realist perspective and critique to the sphere of contemporary contractual governance, but - rather - to translate its aims into a more reflexive set of instruments of legal critique. Even if Globalization has led to a dramatic denationalization of many regulatory fields and functions, it is still not clear, whether and how Globalization replaces, complements or aggravates transformations of societal governance, with and through contract

    The colour dipole approach to small-x processes

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    We explain why it is possible to formulate a wide variety of high energy (small-x) photon-proton processes in terms of a universal dipole cross section and compare and contrast various parameterizations of this function that exist in the literature.Comment: 6 pages, latex, 2 figures. Contribution to Durham Collider Workshop (Sept 99) proceeding
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