Double-logarithmic two-loop self-energy corrections to the Lamb shift
Double-logarithmic two-loop self-energy corrections to the Lamb shift
Self-energy corrections involving logarithms of the parameter $Z\ensuremath{\alpha}$ can often be derived within a simplified approach, avoiding calculational difficulties typical of the problematic nonlogarithmic corrections (as customary in bound-state quantum electrodynamics, we denote by Z the nuclear charge number, and by $\ensuremath{\alpha}$ the fine-structure constant). For some logarithmic corrections, it …