2,317 research outputs found

    Finite Mass Effect on Two Photon Processes in Hydrogenic Systems: Effective Scalar Photon Interaction

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    We consider a hydrogenic system with a nucleus of finite mass. The coupling of the radiation field to the center of mass motion gives rise to an effective scalar type coupling. This induced scalar photon interaction emerges as a correction in competition with the usual multipole interactions. This effect is particularly important in positronium where the electric quadrupole interaction is totally suppressed. We illustrate this effect with the two-photon decay of metastable hydrogenic systems.Comment: 12 pages, Latex, no figure. Version to appear in Phys. Lett.

    Further implications of the Bessis-Moussa-Villani conjecture

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    We find further implications of the BMV conjecture, which states that for hermitian matrices A and B, the function Tr exp(A - t B) is the Laplace transform of a positive measure.Comment: LaTeX, 8 page

    In support of shorter hospital stays for selected high‐risk obstetric patients

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135274/1/ijgo105.pd

    Superposition in branching allocation problems

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    Gauge Invariant Geometric Variables For Yang-Mills Theory

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    In a previous publication [1], local gauge invariant geometric variables were introduced to describe the physical Hilbert space of Yang-Mills theory. In these variables, the electric energy involves the inverse of an operator which can generically have zero modes, and thus its calculation is subtle. In the present work, we resolve these subtleties by considering a small deformation in the definition of these variables, which in the end is removed. The case of spherical configurations of the gauge invariant variables is treated in detail, as well as the inclusion of infinitely heavy point color sources, and the expression for the associated electric field is found explicitly. These spherical geometries are seen to correspond to the spatial components of instanton configurations. The related geometries corresponding to Wu-Yang monopoles and merons are also identified.Comment: 21 pp. in plain TeX. Uses harvmac.te

    Proton-Induced Background Studies for a Satellite Gamma-Ray Experiment

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    This work was supported by the National Science Foundation Grant NSF PHY 78-22774 A02 & A03 and by Indiana Universit

    Combined effect of coherent Z exchange and the hyperfine interaction in atomic PNC

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    The nuclear spin-dependent parity nonconserving (PNC) interaction arising from a combination of the hyperfine interaction and the coherent, spin-independent, PNC interaction from Z exchange is evaluated using many-body perturbation theory. For the 6s-7s transition in 133Cs, we obtain a result that is about 40% smaller than that found previously by Bouchiat and Piketty [Phys. Lett. B 269, 195 (1991)]. Applying this result to 133Cs, leads to an increase in the experimental value of nuclear anapole moment and exacerbates differences between constraints on PNC meson coupling constants obtained from the Cs anapole moment and those obtained from other nuclear parity violating experiments. Nuclear spin-dependent PNC dipole matrix elements, including contributions from the combined weak-hyperfine interaction, are also given for the 7s-8s transition in 211Fr and for transitions between ground-state hyperfine levels in K, Rb, Cs, Ba+, Au, Tl, Fr, and Ra+.Comment: Revtex4 preprint 19 pages 4 table

    Studies on Hypoxia: XII. Detrimental Effects of Synthetic Polyribonucleotides on Epiphyseal Plates of Rats Exposed to Hypoxia

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    The effect of different doses of polyadenylic and polyuridylic acids (poly A:U) was studied in control rats and in rats exposed to hypoxia. In the control rats, administration of different doses of poly A:U did not change the thickness of the epiphyseal plate or increase the incorporation of 3H-phenylalanine as judged using radioautography. Rats exposed to hypoxia showed a significant dose-related reduction in the thickness of the epiphyseal plate and 3H-phenylalanine incorporation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67926/2/10.1177_00220345760550041701.pd

    Atom gratings produced by large angle atom beam splitters

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    An asymptotic theory of atom scattering by large amplitude periodic potentials is developed in the Raman-Nath approximation. The atom grating profile arising after scattering is evaluated in the Fresnel zone for triangular, sinusoidal, magneto-optical, and bichromatic field potentials. It is shown that, owing to the scattering in these potentials, two \QTR{em}{groups} of momentum states are produced rather than two distinct momentum components. The corresponding spatial density profile is calculated and found to differ significantly from a pure sinusoid.Comment: 16 pages, 7 figure
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