1,619 research outputs found

    An investigation of screwiness in hadronic final states from DELPHI

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    A recent theoretical model by Andersson et al. proposes that soft gluons order themselves in the form of a helix at the end of the QCD cascades. The Authors of the model present a measure of the rapidity-azimuthal angle correlation, which they call screwiness. We searched for such a signal in DELPHI data, and found no evidence for screwiness

    High Transverse Momentum Physics at the Large Hadron Collider

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    This note summarizes many detailed physics studies done by the ATLAS and CMS Collaborations for the LHC, concentrating on processes involving the production of high mass states. These studies show that the LHC should be able to elucidate the mechanism of electroweak symmetry breaking and to study a variety of other topics related to physics at the TeV scale. In particular, a Higgs boson with couplings given by the Standard Model is observable in several channels over the full range of allowed masses. Its mass and some of its couplings will be determined. If supersymmetry is relevant to electroweak interactions, it will be discovered and the properties of many supersymmetric particles elucidated. Other new physics, such as the existence of massive gauge bosons and extra dimensions can be searched for extending existing limits by an order of magnitude or more.Comment: Authors listed are the editor

    Design of a novel instrument for active neutron interrogation of artillery shells

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    The most common explosives can be uniquely identified by measuring the elemental H/N ratio with a precision better than 10%. Monte Carlo simulations were used to design two variants of a new prompt gamma neutron activation instrument that can achieve this precision. The instrument features an intense pulsed neutron generator with precise timing. Measuring the hydrogen peak from the target explosive is especially challenging because the instrument itself contains hydrogen, which is needed for neutron moderation and shielding. By iterative design optimization, the fraction of the hydrogen peak counts coming from the explosive under interrogation increased from 53(-7)(-7)% to 74(-10)(+8)% (statistical only) for the benchmark design. In the optimized design variants, the hydrogen signal from a high-explosive shell can be measured to a statistics-only precision better than 1% in less than 30 minutes for an average neutron production yield of 10(9) n/s.Peer reviewe

    Effect of Gamma-Ray Energy on Image Quality in Passive Gamma Emission Tomography of Spent Nuclear Fuel

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    Gamma-ray images of VVER-440 and SVEA-96 spent nuclear fuel assemblies were reconstructed using the filtered backprojection algorithm from measurements with a passive gamma emission tomography prototype instrument at Finnish nuclear power plants. Image quality evaluation criteria based on line profiles through the reconstructed image are used to evaluate image quality for spent fuel assemblies with different cooling times, and thus different mixtures of gamma-ray emitting isotopes. Image characteristics at the locations of water channels and central fuel pins are compared in two gamma-ray energy windows, 600-700 and >700keV, for cooling times up to 10 years for SVEA-96 fuel and 24.5 years for VVER-440 fuel. For SVEA-96 fuel, images in the >700-keV gamma-ray energy window present better water-to-fuel contrast for all investigated cooling times. For VVER-440, images in the >700-keV gamma-ray energy window have higher water-to-fuel contrast up to and including a cooling time of 18.5 years, whereas the water-to-fuel contrast of the images taken in the two gamma-ray energy windows is equivalent for a cooling time of 24.5 years. Images reconstructed from higher energy gamma rays such as those in the >700-keV energy window present better water-to-fuel contrast in fuel cooled for up to 20 years and thus have the most potential for missing fuel pin detection.Peer reviewe

    Secure Cloud Connectivity for Scientific Applications

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    Cloud computing improves utilization and flexibility in allocating computing resources while reducing the infrastructural costs. However, in many cases cloud technology is still proprietary and tainted by security issues rooted in the multi-user and hybrid cloud environment. A lack of secure connectivity in a hybrid cloud environment hinders the adaptation of clouds by scientific communities that require scaling-out of the local infrastructure using publicly available resources for large-scale experiments. In this article, we present a case study of the DII-HEP secure cloud infrastructure and propose an approach to securely scale-out a private cloud deployment to public clouds in order to support hybrid cloud scenarios. A challenge in such scenarios is that cloud vendors may offer varying and possibly incompatible ways to isolate and interconnect virtual machines located in different cloud networks. Our approach is tenant driven in the sense that the tenant provides its connectivity mechanism. We provide a qualitative and quantitative analysis of a number of alternatives to solve this problem. We have chosen one of the standardized alternatives, Host Identity Protocol, for further experimentation in a production system because it supports legacy applications in a topologically-independent and secure way.Peer reviewe

    BCVEGPY: An Event Generator for Hadronic Production of the B_c Meson

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    We have written a Fortran programme BCVEGPY, which is an event generator for the hadronic production of the BcB_c meson through the dominant hard subprocess ggBc(Bc)+b+cˉgg\to B_c(B_c^*) +b+\bar{c}. To achieve a compact programme, we have written the amplitude of the subprocess with the particle helicity technique and made it as symmetric as possible, by decomposing the gluon self couplings and then applying the symmetries. To check the programme, various cross sections of the subprocess have been computed numerically and compared with those in the literature. BCVEGPY is written in a PYTHIA-compatible format, thus it is easy to implement in PYTHIA.Comment: 47 pages, 12 figure

    A drugs marketing company salary system design

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    内容摘要薪酬制度是企业人力资源管理的核心。它体现了企业人力资源价值的分配和人力资源管理理念。企业在设计新酬制度的过程中,必须在其经营战略的框架下,通过对其薪酬组成元素的优化配置,以整体薪酬制度的形式来发挥薪酬效能,以支持企业战略目标的实现和满足员工多元化的需求。企业营销人员薪酬制度问题,是营销管理中的一个重要课题,建立一套科学、有效的销售人员薪酬制度并非易事。世界上没有通用、固定不变的某种销售薪酬制度,它将随企业营销战略、模式、渠道,所提供的产品或服务性质,细分客户群和客户类型等的不同而存在差异。可以说,不同类型的销售人员、不同类型的企业、不同类型的市场,就有不同类型的薪酬制度。本文从薪酬的基...ABSTRACT Salary system is the core of human resource management for enterprise. It expresses the enterprise’s value distribution and management idea of human resource. When an enterprise initiates its salary system, it is very important for them to optimize the allocation of salary elements based on the enterprise’s operation strategy so as to maximize the efficiency of salary system by way ...学位:工商管理硕士院系专业:管理学院高级经理教育中心(EMBA项目)_管理经济学学号:X20031503
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