640 research outputs found

    QED theory of the nuclear recoil effect in atoms

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    The quantum electrodynamic theory of the nuclear recoil effect in atoms to all orders in \alpha Z is formulated. The nuclear recoil corrections for atoms with one and two electrons over closed shells are considered in detail. The problem of the composite nuclear structure in the theory of the nuclear recoil effect is discussed.Comment: 20 pages, 6 figures, Late

    Virial relations for the Dirac equation and their applications to calculations of H-like atoms

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    Virial relations for the Dirac equation in a central field and their applications to calculations of H-like atoms are considered. It is demonstrated that using these relations allows one to evaluate various average values for a hydrogenlike atom. The corresponding relations for non-diagonal matrix elements provide an effective method for analytical evaluations of infinite sums that occur in calculations based on using the reduced Coulomb-Green function. In particular, this method can be used for calculations of higher-order corrections to the hyperfine splitting and to the g factor in hydrogenlike atoms.Comment: Invited talk at PSAS 2002, St.Petersburg; 19 pages, 1 figur

    Interelectronic-interaction effect on the transition probability in high-Z He-like ions

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    The interelectronic-interaction effect on the transition probabilities in high-Z He-like ions is investigated within a systematic quantum electrodynamic approach. The calculation formulas for the interelectronic-interaction corrections of first order in 1/Z are derived using the two-time Green function method. These formulas are employed for numerical evaluations of the magnetic transition probabilities in heliumlike ions. The results of the calculations are compared with experimental values and previous calculations

    Two-loop self-energy contribution to the Lamb shift in H-like ions

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    The two-loop self-energy correction is evaluated to all orders in Z\alpha for the ground-state Lamb shift of H-like ions with Z >= 10, where Z is the nuclear charge number and \alpha is the fine structure constant. The results obtained are compared with the analytical values for the Z\alpha-expansion coefficients. An extrapolation of the all-order numerical results to Z=1 is presented and implications of our calculation for the hydrogen Lamb shift are discussed

    QED corrections to the parity-nonconserving 6s-7s amplitude in 133^{133}Cs

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    The complete gauge-invariant set of the one-loop QED corrections to the parity-nonconserving 6s-7s amplitude in 133^{133}Cs is evaluated to all orders in αZ\alpha Z using a local version of the Dirac-Hartree-Fock potential. The calculations are peformed in both length and velocity gauges for the absorbed photon. The total binding QED correction is found to be -0.27(3)%, which differs from previous evaluations of this effect. The weak charge of 133^{133}Cs, derived using two most accurate values of the vector transition polarizability β\beta, is QW=72.57(46)Q_W=-72.57(46) for β=26.957(51)aB3\beta = 26.957(51) a_{\rm B}^3 and QW=73.09(54)Q_W=-73.09(54) for β=27.15(11)aB3\beta= 27.15(11)a_{\rm B}^3 . The first value deviates by 1.1σ1.1\sigma from the prediction of the Standard Model, while the second one is in perfect agreement with it.Comment: 4 pages, 1 figure, 2 table

    Two-loop self-energy correction in H-like ions

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    A part of the two-loop self-energy correction, the so-called P term, is evaluated numerically for the 1s state to all orders in Z\alpha. Our calculation, combined with the previous investigation [S. Mallampalli and J. Sapirstein, Phys. Rev. A 57, 1548 (1998)], yields the total answer for the two-loop self-energy correction in H-like uranium and bismuth. As a result, the major uncertainty is eliminated from the theoretical prediction for the Lamb shift in these systems. The total value of the ground-state Lamb shift in H-like uranium is found to be 463.93(50) eV.Comment: RevTex, 29 pages, 5 figure
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