3,202 research outputs found

    Meson PVV Interactions are determined by Quark Loops

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    We show that all abnormal parity three-body meson interactions can be adequately described by quark loops, evaluated at zero external momentum, with couplings determined by U(Nf)U(N_f) symmetry. We focus primarily on radiative meson decays which involve one pseudoscalar. The agreement with experiment for non-rare decays is surprisingly good and requires very few parameters, namely the coupling constants gπqqg_{\pi qq} and gρqqg_{\rho qq} and some mixing angles. This agreement extends to some three-body decays that are dominated by pion pairs in a P-wave state.Comment: 21 pages, Revtex, one figur

    Cerebral aneurysm treatment: modern neurovascular techniques.

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    Endovascular treatment of cerebral aneurysm continues to evolve with the development of new technologies. This review provides an overview of the recent major innovations in the neurointerventional space in recent years

    Momentum and Coordinate Space Three-nucleon Potentials

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    In this paper we give explicit formulae in momentum and coordinate space for the three-nucleon potentials due to ρ\rho and π\pi meson exchange, derived from off-mass-shell meson-nucleon scattering amplitudes which are constrained by the symmetries of QCD and by the experimental data. Those potentials have already been applied to nuclear matter calculations. Here we display additional terms which appear to be the most important for nuclear structure. The potentials are decomposed in a way that separates the contributions of different physical mechanisms involved in the meson-nucleon amplitudes. The same type of decomposition is presented for the ππ\pi - \pi TM force: the Δ\Delta, the chiral symmetry breaking and the nucleon pair terms are isolated.Comment: LATEX, 33 pages, 3 figures (available as postscript files upon request

    The Impact of the Safeguard Anti-Ballistic Missile System Construction on Northeastern North Dakota

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    Federal defense projects have let to rapid population changes in many communities. These communities often have experienced rapid growth during the construction and installation phase, followed by a population decrease when the project became operational and labor requirements declined. Large industrial construction projects (e.g., construction of coal conversion plants) may confront other communities with similar adjustment problems.Community/Rural/Urban Development,

    The Land Use Recodification Project

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    Economic Feasibility of Utilizing Waste-Water Heat from Coal-Fired Electrical Generating Plants in Commercial Greenhouses in North Dakota

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    This study provides information on the economic feasibility of establishing commercial greenhouses utilizing waste-water heat in North Dakota.Production Economics, Resource /Energy Economics and Policy,

    Charge-Symmetry Breaking and the Two-Pion-Exchange Two-Nucleon Interaction

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    Charge-symmetry breaking in the nucleon-nucleon force is investigated within an effective field theory, using a classification of isospin-violating interactions based on power-counting arguments. The relevant charge-symmetry-breaking interactions corresponding to the first two orders in the power counting are discussed, including their effects on the 3He-3H binding-energy difference. The static charge-symmetry-breaking potential linear in the nucleon-mass difference is constructed using chiral perturbation theory. Explicit formulae in momentum and configuration spaces are presented. The present work completes previously obtained results.Comment: 15 pages, 2 figure

    Charge-Symmetry-Breaking Three-Nucleon Forces

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    Leading-order three-nucleon forces that violate isospin symmetry are calculated in Chiral Perturbation Theory. The effect of the charge-symmetry-breaking three-nucleon force is investigated in the trinucleon systems using Faddeev calculations. We find that the contribution of this force to the 3He - 3H binding-energy difference is approximately 5 keV.Comment: 14 pages, 3 figure
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