1,826 research outputs found

    Exchange and relaxation effects in low-energy radiationless transitions

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    The effect on low-energy atomic inner-shell Coster-Kronig and super Coster-Kronig transitions that is produced by relaxation and by exchange between the continuum electron and bound electrons was examined and illustrated by specific calculations for transitions that deexcite the 3p vacancy state of Zn. Taking exchange and relaxation into account is found to reduce, but not to eliminate, the discrepancies between theoretical rates and measurements

    Interpretation of the silver L X-ray spectrum

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    Silver L X-ray energies were calculated using theoretical binding energies from relaxed orbital relativistic Hartree-Fock-Slater calculations. Theoretical X-ray energies are compared with experimental results

    Atomic electron energies including relativistic effects and quantum electrodynamic corrections

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    Atomic electron energies have been calculated relativistically. Hartree-Fock-Slater wave functions served as zeroth-order eigenfunctions to compute the expectation of the total Hamiltonian. A first order correction to the local approximation was thus included. Quantum-electrodynamic corrections were made. For all orbitals in all atoms with 2 less than or equal to Z less than or equal to 106, the following quantities are listed: total energies, electron kinetic energies, electron-nucleus potential energies, electron-electron potential energies consisting of electrostatic and Breit interaction (magnetic and retardation) terms, and vacuum polarization energies. These results will serve for detailed comparison of calculations based on other approaches. The magnitude of quantum electrodynamic corrections is exhibited quantitatively for each state

    Theoretical L-shell Coster-Kronig energies 11 or equal to z or equal to 103

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    Relativistic relaxed-orbital calculations of L-shell Coster-Kronig transition energies have been performed for all possible transitions in atoms with atomic numbers. Hartree-Fock-Slater wave functions served as zeroth-order eigenfunctions to compute the expectation of the total Hamiltonian. A first-order approximation to the local approximation was thus included. Quantum-electrodynamic corrections were made. Each transition energy was computed as the difference between results of separate self-consistent-field calculations for the initial, singly ionized state and the final two-hole state. The following quantities are listed: total transition energy, 'electric' (Dirac-Hartree-Fock-Slater) contribution, magnetic and retardation contributions, and contributions due to vacuum polarization and self energy

    LARGE-SCALE WIND-TUNNEL TESTS IN GROUND EFFECT OF A 35 DEG SWEPTBACK WING JET TRANSPORT MODEL EQUIPPED WITH BLOWING BOUNDARY-LAYER-CONTROL TRAILING- AND LEADING-EDGE FLAPS

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    Wind tunnel test of ground effect of 35-deg swept- back wing jet transport equipped with boundary layer control, trailing & leading edge flap

    Large-Scale Wind-Tunnel Tests and Evaluation of the Low-Speed Performance of a 35 deg Sweptback Wing Jet Transport Model Equipped with a Blowing Boundary-Layer-Control Flap and Leading-Edge Slat

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    A wind-tunnel investigation was conducted to determine the effect of trailing-edge flaps with blowing-type boundary-layer control and leading-edge slats on the low-speed performance of a large-scale jet transport model with four engines and a 35 deg. sweptback wing of aspect ratio 7. Two spanwise extents and several deflections of the trailing-edge flap were tested. Results were obtained with a normal leading-edge and with full-span leading-edge slats. Three-component longitudinal force and moment data and boundary-layer-control flow requirements are presented. The test results are analyzed in terms of possible improvements in low-speed performance. The effect on performance of the source of boundary-layer-control air flow is considered in the analysis

    Critical Scale-invariance in Healthy Human Heart Rate

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    We demonstrate the robust scale-invariance in the probability density function (PDF) of detrended healthy human heart rate increments, which is preserved not only in a quiescent condition, but also in a dynamic state where the mean level of heart rate is dramatically changing. This scale-independent and fractal structure is markedly different from the scale-dependent PDF evolution observed in a turbulent-like, cascade heart rate model. These results strongly support the view that healthy human heart rate is controlled to converge continually to a critical state.Comment: 9 pages, 3 figures. Phys. Rev. Lett., to appear (2004

    Amplitude analysis of reactions pi(-)p->etapi(-)p and pi(-)p->etapi(0)n on polarized target and the exotic 1-+ meson

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    Recently several experimental groups analysed data on π−p→ηπ−p\pi^- p \to \eta \pi^- p and π−p→ηπ0n\pi^- p \to \eta \pi^0 n reactions with exotic 1−+1^{-+} PP-wave and found a conflicting evidence for an exotic meson I=11−+(1405)I=1 1^{-+} (1405). High statistics data on these reactions are presently analysed by BNL E852 Collaboration. All these analyses are based on the crucial assumption that the production amplitudes do not depend on nucleon spin. This assumption is in sharp conflict with the results of measurements of π−p→π−π+n\pi^- p \to \pi^- \pi^+ n, π+n→π+π−p\pi^+ n \to \pi^+ \pi^- p and K+n→K+π−pK^+ n \to K^+ \pi^- p on polarized targets at CERN which find a strong dependence of production amplitudes on nucleon spin. To ascertain the existence of exotic meson 1−+(1405)1^{-+} (1405), it is necessary to perform a model-independent amplitude analysis of reactions π−p→ηπ−p\pi^- p \to \eta \pi^- p and π−p→ηπ0n\pi^- p \to \eta\pi^0 n. We demonstrate that measurements of these reactions on transversely polarized targets enable the required model independent amplitude analysis without the assumption that production amplitudes are independent on nucleon spin. We suggest that high statistics measurements of reactions π−p→ηπ−p\pi^- p \to \eta\pi^- p and π−p→ηπ0n\pi^- p \to\eta\pi^0 n be made on polarized targets at BNL and at Protvino IHEP, and that model-independent amplitude analyses of this polarized data be performed to advance hadron spectroscopy on the level of spin dependent production amplitudes.Comment: 23 page
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