A Problematic Set of Two-Loop Self-Energy Corrections

Abstract

We investigate a specific set of two-loop self-energy corrections involving squared decay rates and point out that their interpretation is highly problematic. The corrections cannot be interpreted as radiative energy shifts in the usual sense. Some of the problematic corrections find a natural interpretation as radiative nonresonant corrections to the natural line shape. They cannot uniquely be associated with one and only one atomic level. While the problematic corrections are rather tiny when expressed in units of frequency (a few Hertz for hydrogenic P levels) and do not affect the reliability of quantum electrodynamics at the current level of experimental accuracy, they may be of importance for future experiments. The problems are connected with the limitations of the so-called asymptotic-state approximation which means that atomic in- and out-states in the S-matrix are assumed to have an infinite lifetime.

12 pages, 3 figures (New J. Phys., in press, submitted 28th May)

References in corpus (3)

• Asymmetry of the natural line profile for the hydrogen atom
• Two-Loop Self-Energy Corrections to the Fine-Structure
• Nonresonant corrections to the 1s-2s two-photon resonance for the hydrogen atom

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• Two-Loop Bethe Logarithms for Higher Excited S Levels
• Two-Loop QED Bound-State Calculations and Squared Decay Rates
• Separation of Transitions with Two Quantum Jumps from Cascades
• Two-Loop Effects and Current Status of the 4He+ Lamb Shift
• Techniques in Analytic Lamb Shift Calculations
• Radiative corrections to the level width in the presence of magnetic field