1,968 research outputs found

    Numerical simulations of bent, disrupted radio jets

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    We present preliminary results from three-dimensional hydrodynamical simulations designed to investigate the physics of jet bending and disruption. The specific scenario considered here involves a mildly supersonic jet crossing a contact discontinuity at the interface between the interstellar medium (ISM) and the intercluster medium (ICM) and then encountering a cross-wind in the ICM. The resultant morphologies show many of the features observed in radio sources including jet flaring, bending, and extended tails

    On the impact of dimension-eight SMEFT operators on Higgs measurements

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    Using the production of a Higgs boson in association with a WW boson as a test case, we assess the impact of dimension-8 operators within the context of the Standard Model Effective Field Theory. Dimension-8--SM-interference and dimension-6-squared terms appear at the same order in an expansion in 1/Λ1/\Lambda, hence dimension-8 effects can be treated as a systematic uncertainty on the new physics inferred from analyses using dimension-6 operators alone. To study the phenomenological consequences of dimension-8 operators, one must first determine the complete set of operators that can contribute to a given process. We accomplish this through a combination of Hilbert series methods, which yield the number of invariants and their field content, and a step-by-step recipe to convert the Hilbert series output into a phenomenologically useful format. The recipe we provide is general and applies to any other process within the dimension ≤8\le 8 Standard Model Effective Theory. We quantify the effects of dimension-8 by turning on one dimension-6 operator at a time and setting all dimension-8 operator coefficients to the same magnitude. Under this procedure and given the current accuracy on σ(pp→h W+)\sigma(pp \to h\,W^+), we find the effect of dimension-8 operators on the inferred new physics scale to be small, O(few %)\mathcal O(\text{few}\,\%), with some variation depending on the relative signs of the dimension-8 coefficients and on which dimension-6 operator is considered. The impact of the dimension-8 terms grows as σ(pp→h W+)\sigma(pp \to h\,W^+) is measured more accurately or (more significantly) in high-mass kinematic regions. We provide a FeynRules implementation of our operator set to be used for further more detailed analyses.Comment: More operator coefficient choices explored, bugs in FeynRules implementation correcte

    A numerical simulation of galaxy subcluster mergers

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    We present preliminary results of a 3-D numerical simulation of two merging subclusters of galaxies. By self-consistently modelling the intracluster gas and dark matter dynamics, we hope to gain insight as to how the dynamics of both relate to such observables as the cluster x-ray emission, radio source morphology, and velocity dispersions

    Weighing evidence ‘steampunk’ style via the Meta-Analyser

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    The funnel plot is a graphical visualization of summary data estimates from a meta-analysis, and is a useful tool for detecting departures from the standard modeling assumptions. Although perhaps not widely appreciated, a simple extension of the funnel plot can help to facilitate an intuitive interpretation of the mathematics underlying a meta-analysis at a more fundamental level, by equating it to determining the center of mass of a physical system. We used this analogy to explain the concepts of weighing evidence and of biased evidence to a young audience at the Cambridge Science Festival, without recourse to precise definitions or statistical formulas and with a little help from Sherlock Holmes! Following on from the science fair, we have developed an interactive web-application (named the Meta-Analyser) to bring these ideas to a wider audience. We envisage that our application will be a useful tool for researchers when interpreting their data. First, to facilitate a simple understanding of fixed and random effects modeling approaches; second, to assess the importance of outliers; and third, to show the impact of adjusting for small study bias. This final aim is realized by introducing a novel graphical interpretation of the well-known method of Egger regression

    Numerical models of jet disruption in cluster cooling flows

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    We present a coherent picture for the formation of the observed diverse radio morphological structures in dominant cluster galaxies based on the jet Mach number. Realistic, supersonic, steady-state cooling flow atmospheres are evolved numerically and then used as the ambient medium through which jets of various properties are propagated. Low Mach number jets effectively stagnate due to the ram pressure of the cooling flow atmosphere while medium Mach number jets become unstable and disrupt in the cooling flow to form amorphous structures. High Mach number jets manage to avoid disruption and are able to propagate through the cooling flow

    Australia\u27s Evolving Defence Requirements Over the Coming Decade

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    US Strategic Planning for the Indo-Pacific: Implications for ANZUS

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    Patterns of successful CRM:More about solutions than software

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    Customer Relationship Management (CRM), much hyped during the dot com years, has always been more than software. The CRM industry was tainted by high profile missteps, partly due to its focus on software, rather than solutions (Patton, 2001). However, managers must understand that CRM is a solution, not software that integrates both technology and operational improvements. With the ability to coordinate across all customer contact points, decision makers must recognize that CRM is an organizational process that integrates information from previously disparate channels (sales, marketing, customer service via phone, text chat, or web) to better serve customers (Day and Van der Bulte, 2002). This paper examines the fundamentals of CRM, its goals and common pitfalls, and its prerequisite for this long-term, successful implementation with the goal of extracting patterns of successful CRM deployments

    Australia’s 2009 Defense White Paper

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    Defending Australia in the Asia Pacific Century represents Canberra’s first concerted attempt to address the security challenges posed by a rising China and regional great-power dynamics. It presents a sober view of the future and an indication of Australia’s determination to prepare for whatever that future may bring
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