11,540 research outputs found

    Determination of the Ī”S=1\Delta S = 1 weak Hamiltonian in the SU(4) chiral limit through topological zero-mode wave functions

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    A new method to determine the low-energy couplings of the Ī”S=1\Delta S=1 weak Hamiltonian is presented. It relies on a matching of the topological poles in 1/m21/m^2 of three-point correlators of two pseudoscalar densities and a four-fermion operator, measured in lattice QCD, to the same observables computed in the Ļµ\epsilon-regime of chiral perturbation theory. We test this method in a theory with a light charm quark, i.e. with an SU(4) flavour symmetry. Quenched numerical measurements are performed in a 2 fm box, and chiral perturbation theory predictions are worked out up to next-to-leading order. The matching of the two sides allows to determine the weak low-energy couplings in the SU(4) limit. We compare the results with a previous determination, based on three-point correlators containing two left-handed currents, and discuss the merits and drawbacks of the two procedures.Comment: 38 pages, 9 figure

    Weak low-energy couplings from topological zero-mode wavefunctions

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    We discuss a new method to determine the low-energy couplings of the Ī”S=1\Delta S=1 weak Hamiltonian in the Ļµ\epsilon-regime. It relies on a matching of the topological poles in 1/m21/m^2 of three-point functions of two pseudoscalar densities and a four-fermion operator computed in lattice QCD, to the same observables in the Chiral Effective Theory. We present the results of a NLO computation in chiral perturbation theory of these correlation functions together with some preliminary numerical results.Comment: 7 pages. Contribution to Lattice 200

    Generalised verification of the observer property in discrete event systems

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    The observer property is an important condition to be satisfied by abstractions of Discrete Event Systems (DES) models. This paper presents a generalised version of a previous algorithm which tests if an abstraction of a DES obtained through natural projection has the observer property. The procedure called OP-verifier II overcomes the limitations of the previously proposed verifier while keeping its computational complexity. Results are illustrated by a case study of a transfer line system

    Generalised verification of the observer property in discrete event systems

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    The observer property is an important condition to be satisfied by abstractions of Discrete Event Systems (DES) models. This paper presents a generalised version of a previous algorithm which tests if an abstraction of a DES obtained through natural projection has the observer property. The procedure called OP-verifier II overcomes the limitations of the previously proposed verifier while keeping its computational complexity. Results are illustrated by a case study of a transfer line system

    Verification of the observer property in discrete event systems

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    The observer property is an important condition to be satisfied by abstractions of Discrete Event System (DES) models. This technical note presents a new algorithm that tests if an abstraction of a DES obtained through natural projection has the observer property. The procedure, called OP-Verifier, can be applied to (potentially nondeterministic) automata, with no restriction on the existence of cycles of 'non-relevant' events. This procedure has quadratic complexity in the number of states. The performance of the algorithm is illustrated by a set of experiments

    Visualizing the 3D Polar Power Patterns and Excitations of Planar Arrays with Matlab

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    [Abstrac] This paper discusses the use of Matlab to create three-dimensional polar plots of the power patterns of planar arrays together with 3D plots of the amplitudes and phases of their excitations. A few lines of Matlab M-code suffice to create complex plots

    Effects of Measurement Distance on Measurements of Symmetrically Shaped Patterns Generated by Line Sources

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    [Abstract] Symmetrically shaped patterns, generated by real continuous linear apertures derived from Taylor distributions, resemble Taylor sum patterns in regard to the distance-dependence of their sidelobe heights. Their ripple shows negligible near-field degradation. If the aperture distribution is complex, however, the ripple and sidelobe levels show previously unreported degradation behavior, including a lowering of the first sidelobe level

    The Impact of Permutable Configurations on Distributed Systems

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    In recent years, much research has been devoted to the study of DNS; however, few have visualized the structured unification of linked lists and sen- sor networks. After years of structured research into agents, we prove the investigation of agents, which embodies the confusing principles of algorithms. Here we present a heuristic for ambimorphic configurations (RHUS), which we use to dis- prove that replication and thin clients are often in-compatible
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