1,530 research outputs found

    Nonlinear metrology with a quantum interface

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    We describe nonlinear quantum atom-light interfaces and nonlinear quantum metrology in the collective continuous variable formalism. We develop a nonlinear effective Hamiltonian in terms of spin and polarization collective variables and show that model Hamiltonians of interest for nonlinear quantum metrology can be produced in 87^{87}Rb ensembles. With these Hamiltonians, metrologically relevant atomic properties, e.g. the collective spin, can be measured better than the "Heisenberg limit" 1/N\propto 1/N. In contrast to other proposed nonlinear metrology systems, the atom-light interface allows both linear and non-linear estimation of the same atomic quantities.Comment: 8 pages, 1 figure

    Probability Bifurcations of L\'evy Bridges

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    A L\'evy bridge--a stable L\'evy stochastic process conditioned to arrive at some state at some later time--can exhibit behavior differing dramatically from the more widely studied case of conditioned Brownian (Gaussian) processes. This difference stems from a structural change in the conditioned probability density at intermediate times as the arrival position varies. This structural shift gives rise to a distinction between "short" and "long" jumps. We explore the consequences of this idea for the statistics of L\'evy vs. Brownian bridges, with applications to the analysis of the boundary-crossing problem and a computationally useful representation of L\'evy bridges that does not carry over directly from the Gaussian case.Comment: 5 pages, 7 figure

    Remarkable case of volvulus in a calf due to aplasia of the mesentery

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    (1) A three-month-old bull-calf dies suddenly as a result of a complicated volvulus. (2) This volvulus is due to a reduction of the mesentery (probably congenital) in a part of the small intestine, which allows a part to slip through the loop formed by a torsion of 180 degrees of the neighbouring loop and so to fix that loop.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.ab202

    Engineering Quantum States, Nonlinear Measurements, and Anomalous Diffusion by Imaging

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    We show that well-separated quantum superposition states, measurements of strongly nonlinear observables, and quantum dynamics driven by anomalous diffusion can all be achieved for single atoms or molecules by imaging spontaneous photons that they emit via resonance florescence. To generate anomalous diffusion we introduce continuous measurements driven by L\'evy processes, and prove a number of results regarding their properties. In particular we present strong evidence that the only stable L\'evy density that can realize a strictly continuous measurement is the Gaussian.Comment: revtex4-1, 17 pages, 7 eps figure

    IT Enabled Sophistication Banking

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    Globalization of financial markets resulting from both IT (particularly internet standards) and increasing homogeneity of regulation has strongly affected the environment, financial services companies are operating in. Given these changes on the market, innovation is not a choice, but a necessity to survive. Observable today, however, are defensive strategies and poor service quality. In this paper based on investments in trust relationships with customers we propose Sophistication (fit) Banking enabled by IT and qualified staff. While traditional markets are characterized by shrinking margins and declining shareholder values, which can easily be explained by considering the digital character of financial products, new intermediaries for customer-centered Sophistication (fit) Banking have the opportunity of becoming spiders in the web and increasing shareholder values constantly

    Exposure to atmospheric radon.

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    We measured radon (222Rn) concentrations in Iowa and Minnesota and found that unusually high annual average radon concentrations occur outdoors in portions of central North America. In some areas, outdoor concentrations exceed the national average indoor radon concentration. The general spatial patterns of outdoor radon and indoor radon are similar to the spatial distribution of radon progeny in the soil. Outdoor radon exposure in this region can be a substantial fraction of an individual's total radon exposure and is highly variable across the population. Estimated lifetime effective dose equivalents for the women participants in a radon-related lung cancer study varied by a factor of two at the median dose, 8 mSv, and ranged up to 60 mSv (6 rem). Failure to include these doses can reduce the statistical power of epidemiologic studies that examine the lung cancer risk associated with residential radon exposure

    The bunch monitoring system of the HITRAP decelerator

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    Narrow structure in the coherent population trapping resonances in rubidium and Rayleigh scattering

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    The measurement of the coherent-population-trapping (CPT) resonances in uncoated Rb vacuum cells has shown that the shape of the resonances is different in different cells. In some cells the resonance has a complex shape - a narrow Lorentzian structure, which is not power broadened, superimposed on the power broadened CPT resonance. The results of the performed investigations on the fluorescence angular distribution are in agreement with the assumption that the narrow structure is a result of atom interaction with Rayleigh scattering light. The results are interesting for indication of the vacuum cleanness of the cells and building of magnetooptical sensors

    Limits on deeply penetrating particles in the 10(17) eV cosmic ray flux

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    Deeply penetrating particles in the 10 to the 17th power eV cosmic ray flux were investigated. No such events were found in 8.2 x 10 to the 6th power sec of running time. Limits were set on the following: quark-matter in the primary cosmic ray flux; long-lived, weakly interacting particles produced in p-air collisions; the astrophysical neutrino flux. In particular, the neutrino flux limit at 10 to the 17th power eV implies that z, the red shift of maximum activity is 10 in the model of Hill and Schramm

    The structure of EAS at E 0.1 EeV

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    The ratio of extensive air showers (EAS) total shower energy in the electromagnetic channel (E em) to the size of the shower at maximum development (N max) from a direct measurement of shower longitudinal development using the air fluorescence technique was calculated. The values are not inconsistent with values based upon track length integrals of the Gaisser-Hillas formula for shower development or the known relation between shower energy and size at maximum for pure electromagnetic cascades. Using Linsley's estimates for undetected shower energy based on an analysis of a wide variety of cosmic ray data, the following relation for total shower energy E vs N max is obtained. The Gaisser Hillas implied undetected shower energy fractions
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