286 research outputs found

    Low and high-energy properties of scattering amplitudes satisfying geometrical scaling

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    It is shown that the ratio of the slope of the diffraction peak to the total cross-section at infinite energy, B(∞\infty) / σtot\sigma_{tot} (∞\infty), is essentially given by the low and intermediate energy behaviour of the scattering amplitude satisfying geometrical scaling (GS)

    Multichannel Anomaly of the Resonance Pole Parameters Resolved

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    Inspired by anomalies which the standard scattering matrix pole-extraction procedures have produced in a mathematically well defined coupled-channel model, we have developed a new method based solely on the assumption of partial-wave analyticity. The new method is simple and applicable not only to theoretical predictions but to the empirical partial-wave data as well. Since the standard pole-extraction procedures turn out to be the lowest-order term of the proposed method the anomalies are understood and resolved.Comment: 5 page

    How does teachers’ professional agency in the classroom change in the professional transition from early career teachers to more experienced ones?

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    Professional agency is key for teachers’ professional development, for constructing their professional identity, and for promoting student learning. This longitudinal study explored the development of teachers’ (N = 201) sense of professional agency in the classroom in the professional transition from early career teachers to more experienced ones. We used latent profile analysis to examine the individual variation and change in teachers’ sense of professional agency in the classroom in a five-year follow-up. The results showed three distinctive profiles: a high sense of professional agency (64%), a moderate sense of professional agency (32%), and a low sense of professional agency (4%) in the classroom. The changes detected in the three teachers’ sense of professional agency profiles varied. The profiles were associated with teacher groups (i.e., primary teachers, subject teachers, and special education teachers), but not with stress, attrition intention or school size. The results imply that teachers’ sense of professional agency in the classroom does not always increase in tandem with experience, and thus, different kinds of support are needed for cultivating teachers’ sense of professional agency over time.Peer reviewe

    Readout system test benches

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    We propose to develop and exploit versatile multi-purpose Personal Computer-based Test Benches to support the evaluation and design of the basic elements required for digital front-end readout and data transmission systems for an LHC experiment. These test benches will have modular hardware facilities for the operation of new readout system components under realistic conditions, and will implement advanced modern software engineering concepts. They will support components such as fast ADCs, hybrid fibre-optic transceivers, and the prototype VLSI systolic array and data-flow processors currently being developed in national research laboratories and by the emerging European HDTV industry. These efforts would also lay the foundations for projects involving the development of custom-designed VLSI circuits

    The Intrinsic Quantum Nature of Nash Equilibrium Mixtures

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    Every undergraduate textbook in game theory has a chapter discussing the difficulty to interpret the mixed Nash equilibrium strategies. Unlike the usual suggested interpretations made in those textbooks, here we prove that these randomised strategies neither imply that players use some coin flips to make their decisions, nor that the mixtures represent the uncertainty of each player about the others' actions.Instead, the paper demonstrates a fundamental connection between the Nash equilibrium 'randomised' or 'mixed' strategies of classical game theory and the pure quantum states of quantum theory in physics. This link has some key consequences for the meaning of randomised strategies:In the main theorem, I prove that in every mixed Nash equilibrium, each player state of knowledge about his/her own future rational choices is represented by a pure quantum state. This indicates that prior making his/her actual choice, each player must be in a quantum superposition over her/his possible rational choices (in the support of his probability measure). This result notably permits to show that the famous 'indifference condition' that must be satisfied by each player in an equilibrium is actually the condition that ensures each player is in a 'rational epistemic state of ignorance' about her/his own future choice of an action

    A unitary model for meson-nucleon scattering

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    In an effective Lagrangian model employing the K-matrix approximation we extract nucleon resonance parameters. To this end we analyze simultaneously all available data for reactions involving the final states πN\pi N, ππN\pi\pi N, ηN\eta N and KΛK \Lambda in the energy range mN+mπ≀s≀1.9m_N + m_{\pi} \le \sqrt s \le 1.9 GeV. The background contributions are generated consistently from the relevant Feynman amplitudes, thus significantly reducing the number of free parameters.Comment: Revised version. 60 pages, 17 figures. Two figures and a short discussion (\pi N \to \eta N, K \Lambda amplitudes) added, typos and minor errors in the citations correcte
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