5,338 research outputs found

    Searches at LEP2 latest results

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    Searches for the Higgs boson of the Standard Model and supersymmetric models have been performed by the four LEP experiments in the data collected over almost 12 years (August/1989 until November/2000) at centre-of-mass energies varying from 91.2 GeV to 209 GeV. An excess of candidates for the process e/sup +/e/sup -/ to Z* to Z/sup 0/H/sup 0/ was found for Higgs masses near 114 GeV. (9 refs)

    Rare B decays at LEP

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    BIO-ENERGY FROM WINERY BY-PRODUCTS: A NEW MULTIFUNCTIONAL TOOL FOR THE ITALIAN WINE DISTRICTS

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    This paper aims to investigate if the legislation will allow the production of energy from winery by-products and how this can contribute to multifunctionality of the wine makers’ income. A medium size winery was selected and an anaerobic digestor process was simulated using the company’s data. The main methods of financial evaluation were studied to create information to see if the project concepts were valid. The results highlight the positive level of earnings that the project will generate due to the high level of methane included in the pressings that could be transformed in energy, the short period needed for obtaining methane and the recent substantial level of government support both in Green Certificates and financing of the initial cost of the investments.Biomass, winery by-products, multifunctionality, energy, wine district, Agribusiness, Community/Rural/Urban Development, Resource /Energy Economics and Policy,

    Physics-related epistemic uncertainties in proton depth dose simulation

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    A set of physics models and parameters pertaining to the simulation of proton energy deposition in matter are evaluated in the energy range up to approximately 65 MeV, based on their implementations in the Geant4 toolkit. The analysis assesses several features of the models and the impact of their associated epistemic uncertainties, i.e. uncertainties due to lack of knowledge, on the simulation results. Possible systematic effects deriving from uncertainties of this kind are highlighted; their relevance in relation to the application environment and different experimental requirements are discussed, with emphasis on the simulation of radiotherapy set-ups. By documenting quantitatively the features of a wide set of simulation models and the related intrinsic uncertainties affecting the simulation results, this analysis provides guidance regarding the use of the concerned simulation tools in experimental applications; it also provides indications for further experimental measurements addressing the sources of such uncertainties.Comment: To be published in IEEE Trans. Nucl. Sc

    Quantifying the unknown: issues in simulation validation and their experimental impact

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    The assessment of the reliability of Monte Carlo simulations is discussed, with emphasis on uncertainty quantification and the related impact on experimental results. Methods and techniques to account for epistemic uncertainties, i.e. for intrinsic knowledge gaps in physics modeling, are discussed with the support of applications to concrete experimental scenarios. Ongoing projects regarding the investigation of epistemic uncertainties in the Geant4 simulation toolkit are reported.Comment: To be published in the Proceedings of the 13th ICATPP Conference on Astroparticle, Particle, Space Physics and Detectors for Physics Applications, Villa Olmo, Como, 3-7 October 201

    Refactoring, reengineering and evolution: paths to Geant4 uncertainty quantification and performance improvement

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    Ongoing investigations for the improvement of Geant4 accuracy and computational performance resulting by refactoring and reengineering parts of the code are discussed. Issues in refactoring that are specific to the domain of physics simulation are identified and their impact is elucidated. Preliminary quantitative results are reported.Comment: To be published in the Proc. CHEP (Computing in High Energy Physics) 201

    Geant4-related R&D for new particle transport methods

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    A R&D project has been launched in 2009 to address fundamental methods in radiation transport simulation and revisit Geant4 kernel design to cope with new experimental requirements. The project focuses on simulation at different scales in the same experimental environment: this set of problems requires new methods across the current boundaries of condensed-random-walk and discrete transport schemes. An exploration is also foreseen about exploiting and extending already existing Geant4 features to apply Monte Carlo and deterministic transport methods in the same simulation environment. An overview of this new R&D associated with Geant4 is presented, together with the first developments in progress.Comment: 4 pages, to appear in proceedings of the Nuclear Science Symposium and Medical Imaging Conference 2009, Orland

    Research in Geant4 electromagnetic physics design, and its effects on computational performance and quality assurance

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    The Geant4 toolkit offers a rich variety of electromagnetic physics models; so far the evaluation of this Geant4 domain has been mostly focused on its physics functionality, while the features of its design and their impact on simulation accuracy, computational performance and facilities for verification and validation have not been the object of comparable attention yet, despite the critical role they play in many experimental applications. A new project is in progress to study the application of new design concepts and software techniques in Geant4 electromagnetic physics, and to evaluate how they can improve on the current simulation capabilities. The application of a policy-based class design is investigated as a means to achieve the objective of granular decomposition of processes; this design technique offers various advantages in terms of flexibility of configuration and computational performance. The current Geant4 physics models have been re-implemented according to the new design as a pilot project. The main features of the new design and first results of performance improvement and testing simplification are presented; they are relevant to many Geant4 applications, where computational speed and the containment of resources invested in simulation production and quality assurance play a critical role.Comment: 4 pages, 4 figures and images, to appear in proceedings of the Nuclear Science Symposium and Medical Imaging Conference 2009, Orland
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