114 research outputs found

    High-energy electrons from the muon decay in orbit: radiative corrections

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    We determine the O(α)\mathcal{O}(\alpha) correction to the energy spectrum of electrons produced in the decay of muons bound in atoms. We focus on the high-energy end of the spectrum that constitutes a background for the muon-electron conversion and will be precisely measured by the upcoming experiments Mu2e and COMET. The correction suppresses the background by about 15\%.Comment: 7 pages, v2: corrected and improved versio

    The analysis of convergence process of voivodships’ efficiency in Poland using the DEA metod

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    Since 1999 – when the new administrative division in Poland was introduced – it has been possible to measure and compare standard of living between Polish and other European regions (NUTS II). In 2004 Poland has joined the European Union. Since that year voivodships have become main beneficiaries of the EU funds. The essential part of that aid is related to the EU cohesion policy (convergence objective). According to the fifth cohesion report “cohesion policy has made a significant contribution to spreading growth and prosperity across the Union, while reducing economic, social and territorial disparitiesâ€. However, the differences in standard of living still remains significant between countries as well as between regions within one country. In many researches the level of welfare is measured using “classic†indicators (GDP per capita, GNI per capita, unemployment rate, etc.). In this paper the authors focus on the regional economies’ efficiency. The efficiency will be measured using the Data Envelopment Analysis. Due to the method used, the efficiency will be measured as relative in nature, i.e. will be compared between voivodships within the period of research. The goal of the paper is to analyze variety of relative voivodships’ efficiency in order to answer the question if the dispersion in efficiency is increasing or decreasing over time.

    Michel decay spectrum for a muon bound to a nucleus

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    The spectrum of electrons from muons decaying in an atomic bound state is significantly modified by their interaction with the nucleus. Somewhat unexpectedly, its first measurement, at the Canadian laboratory TRIUMF, differed from basic theory. We show, using a combination of techniques developed in atomic, nuclear, and high-energy physics, that radiative corrections eliminate the discrepancy. In addition to solving that outstanding problem, our more precise predictions are potentially useful for interpreting future high-statistics muon experiments that aim to search for exotic interactions at 101610^{-16} sensitivity.Comment: 6 pages, 4 figures, Alberta Thy 7-14 v2: Expanded discussion. Journal versio

    Logarithmically enhanced Euler-Heisenberg Lagrangian contribution to the electron gyromagnetic factor

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    Contrary to what was previously believed, two-loop radiative corrections to the gg-factor of an electron bound in a hydrogen-like ion at O(α2(Zα)5)\mathcal{O}\left(\alpha^2 (Z\alpha)^5\right) exhibit logarithmic enhancement. This previously unknown contribution is due to a long-distance light-by-light scattering amplitude. Taking an effective field theory approach, and using the Euler-Heisenberg Lagrangian, we find Δg=(απ)2(Zα)556π135lnZα\Delta g = -\left( \frac{\alpha}{\pi} \right)^2\left(Z\alpha\right)^5 \frac{56 \pi}{135}\ln Z\alpha.Comment: 5 pages, 3 figure

    Potrzeby, możliwości i zagrożenia wynikające z wdrażania transformacji cyfrowej na przykładzie wybranych instytucji publicznych

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    Transformacja cyfrowa otwiera obywatelom nowe możliwości. Dzięki nowoczesnej administracji publicznej urzędy otwarte są dla obywateli całą dobę. Aby było to jednak możliwe konieczne było przejście bardzo długiej drogi, drogi od urzędu papierowego do cyfrowego. Głównym celem niniejszej pracy było określenie jak, czy i jak daleko zaszła transformacja cyfrowa i czy usługi oferowane przez NFZ i ZUS znane są obywatelom. Autor w swojej pracy pokazał jakie usługi cyfrowe aktualnie świadczą obydwie instytucje. Przedstawiono najważniejsze systemy informatyczne dzięki którym możliwa jest integracja z innymi instytucjami publicznymi jak również świadczenie usług dla obywateli. Nowoczesne technologie dają bowiem obywatelom realne oszczędności czasu i wygodę. Dzięki usługom cyfrowym nie ma już również konieczności osobistego stawiennictwa w Urzędzie, a sprawę można załatwić praktycznie z dowolnego miejsca. Autor poddał również analizie szereg czynników mających wpływ na możliwości wykorzystania usług cyfrowych przez obywateli. Głównym elementem pracy było badanie dokonane na pracownikach instytucji publicznych oraz osobach nieaktywnych zawodowo. Przeprowadzona analiza dowiodła, iż obywatele w pozytywny sposób postrzegają instytucje publiczne świadczące usługi cyfrowe. Potwierdziła również, iż potrzeby w zakresie usług cyfrowych zmieniają się wraz z wiekiem obywateli.Digital transformation opens up new opportunities for citizens. Thanks to modern public administration, offices are open to them all the time. However, for this to be possible, it was necessary to go a very long way, from the paper to the digital offices. The main goal of this study was to determine if and how far the digital transformation has taken place and whether the digital services offered by the National Health Fund and the Social Insurance Institution are known to Polish citizens. The author in his work presented what digital services are currently provided by both institutions. The most important IT systems have been presented, thanks to which integration with other public institutions and providing digital services to polish citizens have been possible. Modern technologies provide citizens with real time savings and convenience. Thanks to digital services, there is no need for persona appearance in the Office, and all matters can be settled from virtually anywhere. The author also analysed a number of factors influencing the possibilities of using digital services by citizens. The main element of the work was a survey of employees of public institutions and professionally inactive people. The conducted analysis proved that polish citizens have a positive perception of public institutions providing digital services. It has also been confirmed that people requirements for digital services change with their age

    Measuring the Relative Efficiency of Economic Sectors. Advices for Policy Makers in Poland

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    The main goal of the paper is to present an idea of the Data Envelopment Analysis model and its potential as a method of evaluation of economic sectors efficiency. An empirical part is concentrated on the use of the DEA model to assess efficiency of the construction industry in Poland from 1999 to 2007. The first part of the article addresses the concept of DEA (CCR model) and the next section presents data and results of the analysis. To obtain the outcomes DEA solver software was applied.Głównym celem opracowania jest zaprezentowanie modelu Data Envelopment Analysis (DEA) oraz jego potencjału jako metody oceny efektywności sektorów ekonomicznych gospodarki. Część empiryczna artykułu dotyczy oceny efektywności budownictwa (definiowanego według sekcji PKD) w latach 1999-2007. W pierwszej sekcji artykułu zaprezentowano istotę modelu DEA (w ujęciu CCR). Następnie przedstawiono charakterystykę zmiennych wykorzystanych w analizie oraz wyniki badania. W analizie wsparto się programem DEA solver software
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