1,069 research outputs found

    The influence of non-imaging detector design on heralded ghost-imaging and ghost-diffraction examined using a triggered ICCD came

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    Ghost imaging and ghost diffraction can be realized by using the spatial correlations between signal and idler photons produced by spontaneous parametric down-conversion. If an object is placed in the signal (idler) path, the spatial correlations between the transmitted photons as measured by a single, non-imaging, “bucket” detector and a scanning detector placed in the idler (signal) path can reveal either the image or diffraction pattern of the object, whereas neither detector signal on its own can. The details of the bucket detector, such as its collection area and numerical aperture, set the number of transverse modes supported by the system. For ghost imaging these details are less important, affecting mostly the sampling time required to produce the image. For ghost diffraction, however, the bucket detector must be filtered to a single, spatially coherent mode. We examine this difference in behavour by using either a multi-mode or single-mode fibre to define the detection aperture. Furthermore, instead of a scanning detector we use a heralded camera so that the image or diffraction pattern produced can be measured across the full field of view. The importance of a single mode detection in the observation of ghost diffraction is equivalent to the need within a classical diffraction experiment to illuminate the aperture with a spatially coherent mode

    A Parameterization Invariant Approach to the Statistical Estimation of the CKM Phase α\alpha

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    In contrast to previous analyses, we demonstrate a Bayesian approach to the estimation of the CKM phase α\alpha that is invariant to parameterization. We also show that in addition to {\em computing} the marginal posterior in a Bayesian manner, the distribution must also be {\em interpreted} from a subjective Bayesian viewpoint. Doing so gives a very natural interpretation to the distribution. We also comment on the effect of removing information about B00\mathcal{B}^{00}.Comment: 14 pages, 3 figures, 1 table, minor revision; to appear in JHE

    Quantum Monte Carlo Calculations of Pion Scattering from Li

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    We show that the neutron and proton transition densities predicted by recent quantum Monte Carlo calculations for A=6,7 nuclei are consistent with pion scattering from 6Li and 7Li at energies near the Delta resonance. This has provided a microscopic understanding of the enhancement factors for quadrople excitations, which were needed to describe pion inelastic scattering within the nuclear shell model of Cohen and Kurath.Comment: 10 pages, REVTeX, 3 postscript figures; added calculation of elastic and inelastic pion scattering from 6Li at multiple energie

    Exact multilocal renormalization on the effective action : application to the random sine Gordon model statics and non-equilibrium dynamics

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    We extend the exact multilocal renormalization group (RG) method to study the flow of the effective action functional. This important physical quantity satisfies an exact RG equation which is then expanded in multilocal components. Integrating the nonlocal parts yields a closed exact RG equation for the local part, to a given order in the local part. The method is illustrated on the O(N) model by straightforwardly recovering the η\eta exponent and scaling functions. Then it is applied to study the glass phase of the Cardy-Ostlund, random phase sine Gordon model near the glass transition temperature. The static correlations and equilibrium dynamical exponent zz are recovered and several new results are obtained. The equilibrium two-point scaling functions are obtained. The nonequilibrium, finite momentum, two-time t,tt,t' response and correlations are computed. They are shown to exhibit scaling forms, characterized by novel exponents λRλC\lambda_R \neq \lambda_C, as well as universal scaling functions that we compute. The fluctuation dissipation ratio is found to be non trivial and of the form X(qz(tt),t/t)X(q^z (t-t'), t/t'). Analogies and differences with pure critical models are discussed.Comment: 33 pages, RevTe

    The implications of service quality gaps for strategy implementation

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    This article addresses the problem of service quality strategy implementation and proposes three interrelated models: a static model of the organisation; a comprehensive dynamic model of the implementation process, both synthesised from the literature; and a mixed model, which integrates static and dynamic models. The mixed model is combined with the service quality gaps (SQGs) model, drawn at a previous congress paper, to propose a map of the pattern of SQGs occurring at each implementation stage; the organisational variables that can be manipulated to eliminate SQGs; and several implications to practising managers

    Efimov physics from the functional renormalization group

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    Few-body physics related to the Efimov effect is discussed using the functional renormalization group method. After a short review of renormalization in its modern formulation we apply this formalism to the description of scattering and bound states in few-body systems of identical bosons and distinguishable fermions with two and three components. The Efimov effect leads to a limit cycle in the renormalization group flow. Recently measured three-body loss rates in an ultracold Fermi gas 6^6Li atoms are explained within this framework. We also discuss briefly the relation to the many-body physics of the BCS-BEC crossover for two-component fermions and the formation of a trion phase for the case of three species.Comment: 28 pages, 13 figures, invited contribution to a special issue of "Few-Body Systems" devoted to Efimov physics, published versio

    Surveyed common data access policies preferences amongst European Reference Networks

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    Background: Data sharing amongst existing Rare Disease (RD) registries, even though being a process that presents multiple barriers, would enrich and ease research, as well as facilitate interoperability between the registries themselves. Methods: To understand their preferences on sharing data, we surveyed 24 European Reference Networks (ERNs) from the RD Domain. Results: The answers show that most ERNs are willing to share a set of Common Data Elements for free with authenticated users at an aggregated or pseudonymized level the moment the data is collected. The one exception is the industry sector, to which ERNs prefer to ask for a fee. Objective: Our aim is to create a reference for how most RD registries are willing to share their data, improving the ability of other stakeholders to make informed decisions to make their data interoperable.</p

    Surveyed common data access policies preferences amongst European Reference Networks

    Get PDF
    Background: Data sharing amongst existing Rare Disease (RD) registries, even though being a process that presents multiple barriers, would enrich and ease research, as well as facilitate interoperability between the registries themselves. Methods: To understand their preferences on sharing data, we surveyed 24 European Reference Networks (ERNs) from the RD Domain. Results: The answers show that most ERNs are willing to share a set of Common Data Elements for free with authenticated users at an aggregated or pseudonymized level the moment the data is collected. The one exception is the industry sector, to which ERNs prefer to ask for a fee. Objective: Our aim is to create a reference for how most RD registries are willing to share their data, improving the ability of other stakeholders to make informed decisions to make their data interoperable.</p
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