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Series

2004

Perturbation Techniques

Articles 1 - 4 of 4

Full-Text Articles in Physics

Relativistic And Radiative Corrections To The Mollow Spectrum, Jorg Evers, Ulrich D. Jentschura, Christoph H. Keitel Dec 2004

Relativistic And Radiative Corrections To The Mollow Spectrum, Jorg Evers, Ulrich D. Jentschura, Christoph H. Keitel

Physics Faculty Research & Creative Works

The incoherent inelastic part of the resonance fluorescence spectrum of a laser-driven atom is known as the Mollow spectrum [B. R. Mollow, Phys. Rev. 188, 1969 (1969)]. Starting from this level of description, we discuss theoretical foundations of high-precision spectroscopy using the resonance fluorescence light of strongly laser-driven atoms. Specifically, we evaluate the leading relativistic and radiative corrections to the Mollow spectrum, up to the relative orders of ( Z α )2 and α ( Z α )2 , respectively, and Bloch-Siegert shifts as well as stimulated radiative corrections involving off-resonant virtual states. Complete results are provided for …


Nonrelativistic Qed Approach To The Bound-Electron G Factor, Krzysztof Pachucki, Ulrich D. Jentschura, Vladimir A. Yerokhin Oct 2004

Nonrelativistic Qed Approach To The Bound-Electron G Factor, Krzysztof Pachucki, Ulrich D. Jentschura, Vladimir A. Yerokhin

Physics Faculty Research & Creative Works

Within a systematic approach based on nonrelativistic quantum electrodynamics, we derive the one-loop self-energy correction of order α ( Z α )4 to the bound-electron g factor. In combination with numerical data, this analytic result improves theoretical predictions for the self-energy correction for carbon and oxygen by an order of magnitude. Basing on one-loop calculations, we obtain the logarithmic two-loop contribution of order α2 ( Z α )4 ln [ ( Z α )- 2 ] and the dominant part of the corresponding constant term. The results obtained improve the accuracy of the theoretical predictions for …


Comparison Of Hyperspherical Versus Common-Reaction-Coordinate Close-Coupling Methods For Ion-Atom Collisions At Low Energies, Anh-Thu Le, C. D. Lin, L. F. Errea, L. Mendez, A. Riera, B. Pons Jun 2004

Comparison Of Hyperspherical Versus Common-Reaction-Coordinate Close-Coupling Methods For Ion-Atom Collisions At Low Energies, Anh-Thu Le, C. D. Lin, L. F. Errea, L. Mendez, A. Riera, B. Pons

Physics Faculty Research & Creative Works

We present detailed comparisons between the two quantal approaches--hyperspherical close-coupling and common-reaction-coordinate close-coupling methods--on an exemplary case of He²⁺ + H(1s) collisions at center-of-mass energy from 20eV up to 1.6keV. It is shown that the partial-wave charge-transfer cross sections from the two approaches agree very well at low energy below 200eV down to 30eV. This good agreement is a strong indication of the validity of both methods. The small difference at very low energies and the convergence with respect to the number of channels in both approaches at higher energies are also discussed.


Self-Energy Correction To The Two-Photon Decay Width In Hydrogenlike Atoms, Ulrich D. Jentschura May 2004

Self-Energy Correction To The Two-Photon Decay Width In Hydrogenlike Atoms, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

We investigate the guage invariance of the leading logarithmic radiative correction to the two-photon decay width in hydrogenlike atoms, was investigated. The effective treatment of the correction using a Lamb-shift led to the equivalent results in both the length and velocity gages. The relevant radiative corrections were found to be related to the energies that entered into the propagator denominators, to the Hamiltonian, to the wave functions, and to the energy conservation condition, that holds between two photons. The results show that the dominant radiative correction to the 2S two-photon decay width is about -2.020 536(α/π)(Zα)2 1n[(Zα)-2] …