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Leading logarithmic contribution to the second-order lamb shift induced by the loop-after-loop diagram
1Department of Physics, St. Petersburg State University, Oulianovskaya 1, Petrodvorets, St. Petersburg 198904, Russia.
Physical Review Letters
|April 6, 2001
Summary
This study analytically evaluates a specific contribution to the hydrogen ground-state Lamb shift. Researchers found an additional term, improving agreement between calculation methods.
Area of Science:
- Quantum Electrodynamics (QED)
- Atomic Physics
Background:
- The Lamb shift is a small difference in energy between two energy levels in hydrogen.
- Previous calculations of specific high-order QED contributions have shown discrepancies.
Purpose of the Study:
- To analytically evaluate the order alpha(2)(Zalpha)(6)ln(3)(Zalpha)(-2) contribution to the hydrogen ground-state Lamb shift.
- To resolve discrepancies in theoretical calculations of this specific QED correction.
Main Methods:
- Analytical evaluation of Feynman diagrams, specifically the loop-after-loop diagram.
- High-precision theoretical calculations in quantum electrodynamics.
Main Results:
- An additional contribution of order alpha(2)(Zalpha)(6)ln(3)(Zalpha)(-2) was identified.
- This new finding resolves a discrepancy with previous calculations.
Conclusions:
- The analytical evaluation confirms and refines the theoretical understanding of the hydrogen Lamb shift.
- Achieved agreement between different numerical and analytical methods for this high-order correction.