1,054 research outputs found

    NNLO massive corrections to Bhabha scattering and theoretical precision of BabaYaga@NLO

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    We provide an exact calculation of next-to-next-to-leading order (NNLO) massive corrections to Bhabha scattering in QED, relevant for precision luminosity monitoring at meson factories. Using realistic reference event selections, exact numerical results for leptonic and hadronic corrections are given and compared with the corresponding approximate predictions of the event generator BabaYaga@NLO. It is shown that the NNLO massive corrections are necessary for luminosity measurements with per mille precision. At the same time they are found to be well accounted for in the generator at an accuracy level below the one per mille. An update of the total theoretical precision of BabaYaga@NLO is presented and possible directions for a further error reduction are sketched.Comment: 5 pages, 3 tables, contrib. to proceedings of International Workshop on e+e- collisions: from Phi to Psi, PHIPSI11, BINP, Novosibirsk, Russia, September 19-22, 201

    Automated Reconstruction of Particle Cascades in High Energy Physics Experiments

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    We present a procedure for reconstructing particle cascades from event data measured in a high energy physics experiment. For evaluating the hypothesis of a specific physics process causing the observed data, all possible reconstruction versions of the scattering process are constructed from the final state objects. We describe the procedure as well as examples of physics processes of different complexity studied at hadron-hadron colliders. We estimate the performance by 20 microseconds per reconstructed decay vertex, and 0.6 kByte per reconstructed particle in the decay trees.Comment: 8 pages, 2 figures. Submitted to Computational Science & Discover

    A Development Environment for Visual Physics Analysis

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    The Visual Physics Analysis (VISPA) project integrates different aspects of physics analyses into a graphical development environment. It addresses the typical development cycle of (re-)designing, executing and verifying an analysis. The project provides an extendable plug-in mechanism and includes plug-ins for designing the analysis flow, for running the analysis on batch systems, and for browsing the data content. The corresponding plug-ins are based on an object-oriented toolkit for modular data analysis. We introduce the main concepts of the project, describe the technical realization and demonstrate the functionality in example applications

    EU External Relations: Exclusive Competence Revisited

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    This Article will focus on the question of exclusive competence in the field of EU external relations, especially in the light of recent developments. After a brief discussion on the origins and development of exclusive competence, a distinction will be made between common commercial policy, which has traditionally been the most important area of an explicit “a priori” exclusive competence, and what is often called an implicit exclusive competence, which, as it is today based on some general criteria enshrined in TFEU Article 3(2), may be called “supervening” exclusive competence. With regard to both categories, the main focus will be on recent developments, notably the impact of the Treaty of Lisbon, which introduced the TFEU and its Articles 2 and 3, as well as the case law of the European Court of Justice (“ECJ” or the “Court”) following the entry into force of the Treaty of Lisbon, on December 1, 2009

    Comparison of Fermi-LAT and CTA in the region between 10-100 GeV

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    The past decade has seen a dramatic improvement in the quality of data available at both high (HE: 100 MeV to 100 GeV) and very high (VHE: 100 GeV to 100 TeV) gamma-ray energies. With three years of data from the Fermi Large Area Telescope (LAT) and deep pointed observations with arrays of Cherenkov telescope, continuous spectral coverage from 100 MeV to 10\sim10 TeV exists for the first time for the brightest gamma-ray sources. The Fermi-LAT is likely to continue for several years, resulting in significant improvements in high energy sensitivity. On the same timescale, the Cherenkov Telescope Array (CTA) will be constructed providing unprecedented VHE capabilities. The optimisation of CTA must take into account competition and complementarity with Fermi, in particularly in the overlapping energy range 10-100 GeV. Here we compare the performance of Fermi-LAT and the current baseline CTA design for steady and transient, point-like and extended sources.Comment: Accepted for Publication in Astroparticle Physic

    Could Black Be the New Gold? Design-Driven Challenges in New Sustainable Luxury Materials for Jewelry

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    Is there a new material for use in jewelry, matching gold and precious stones, capable of maintaining the same perception of “preciousness” but that is also more sustainable, ethical, and inexpensive? This article deals with a case study within the European EcoDesign Network research project, aimed at investigating how sustainable design can help prestigious companies pinpoint new materials for the creation of jewelry, focusing on new and environmentally friendly opportunities while preserving their market position and target audience. Qualitative and quantitative analyses were performed. Adopting the exploring design path, a jewelry background analysis pointed out both stereotypes and possible innovations in the jewelry field: an analysis was carried out on the perception of jewels by a panel guided by a cognitive ergonomics specialist, also using the eye-tracking machine to examine participants’ reactions to the jewelry involved in the study, and to establish paradigms of sustainability, preciousness, and innovation. Several meta-project proposals regarding innovations in materials and finishing were hypothesized and tested, following the main guidelines and principles of ecodesign. Lastly, a prototyping phase and some mechanical tests were implemented to verify the hypotheses of innovation. The results allowed the creation of a first set of sustainable jewelry, currently on the market
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