241 research outputs found

    QED theory of transition probabilities and line profiles in highly-charged ions

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    A rigorous QED theory of the spectral line profiles is applied to transition probabilities in few-electron highly charged ions. Interelectron interaction corrections are included as well as radiative corrections. Parity nonconserving (PNC) amplitudes with effective weak interactions between the electrons and nucleus are also considered. QED and interelectron interaction corrections to the PNC amplitudes are derived

    Calculation of quasi-degenerate energy levels of two-electron ions

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    Accurate QED calculations of the interelectron interaction corrections for the (1s2p)21P1(1s2p)2 {}^1 P_1, (1s2p)23P1(1s2p)2 {}^3 P_1 two-electron configurations for ions with nuclear charge numbers 10Z9210\le Z \le 92 are performed within the line profile approach. Total energies of these configurations are evaluated. Employing the fully relativistic treatment based on the {jj--jj} coupling scheme these energy levels become quasi-degenerate in the region Z40Z\le 40. To treat such states within the framework of QED we utilize the line profile approach. The calculations are performed within the Coulomb gauge.Comment: 22 pages, 11 figure

    QED model of the radiation escape from the matter

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    A simple model based on QED is presented for the estimation of contribution of the excited level few-photon decays to the radiation escape from the matter in the epoch of the cosmological hydrogen recombination. It is shown that apart from the widely studied two-photon decays, some specific 3-photon decays can contribute on the level of 0.1% accuracy, required by the recent astrophysical observations.Comment: 21 pages, 3 figures, 1 Tabl

    Asymmetry of the natural line profile for the hydrogen atom

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    The asymmetry of the natural line profile for transitions in hydrogen-like atoms is evaluated within a QED framework. For the Lyman-alpha 1s2p1s-2p absorption transition in neutral hydrogen this asymmetry results in an additional energy shift of 2.929856 Hz. For the 2s1/22p3/22s_{1/2}-2p_{3/2} transition it amounts to -1.512674 Hz. As a new feature this correction turns out to be process dependent. The quoted numbers refer to the Compton-scattering process.Comment: RevTex, 7 Latex pages, 1 figur

    Excited states of the helium-antihydrogen system

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    Potential energy curves for excited leptonic states of the helium-antihydrogen system are calculated within Ritz' variational approach. An explicitly correlated ansatz for the leptonic wave function is employed describing accurately the motion of the leptons (two electrons and positron) in the field of the helium nucleus and of the antiproton with arbitrary orbital angular momentum projection Λ\Lambda onto the internuclear axis. Results for Λ\Lambda=0, 1 and 30 are presented. For quasibound states with large values of Λ\Lambda and rotational quantum numbers J>ΛJ>\Lambda no annihilation and rearrangement decay channels occur, i. e. they are metastable
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