Nonperturbative calculation of the two-loop lamb shift in Li-like ions

Area of Science:

• Atomic Physics
• Quantum Electrodynamics (QED)
• High-Precision Spectroscopy

Background:

• Lamb shift calculations are crucial for testing fundamental physics.
• Heavy, highly charged ions provide unique environments to study QED effects.
• Previous calculations for these systems had significant theoretical uncertainties.

Purpose of the Study:

• To perform an all-order calculation of the two-loop Lamb shift for 2p-2s transitions in heavy Li-like ions.
• To reduce the dominant theoretical uncertainty in these transition energies.
• To provide the first experimental identification of two-loop QED effects in strong binding fields.

Main Methods:

• A theoretical calculation valid to all orders in the nuclear-strength parameter.
• Focus on the two-loop self-energy correction.
• Application to the 2p-2s transition energies in heavy Li-like ions.

Main Results:

• The largest theoretical uncertainty for these transitions has been removed.
• The calculation provides highly accurate predictions for 2p-2s transition energies.
• Enables the experimental identification of two-loop QED effects.

Conclusions:

• The presented calculation significantly advances the precision of theoretical predictions for heavy Li-like ions.
• This work paves the way for precise experimental verification of QED in strong fields.
• Confirms the importance of higher-order QED corrections in understanding atomic structure.