Atomic radiative corrections without QED: role of the zero-point field

Abstract

We derive the atomic radiative corrections predicted by \textsc{qed} using an alternative approach that offers the advantage of physical clarity and transparency. The element that gives rise to these corrections is the fluctuating zero-point radiation field (\textsc{zpf}) of average energy $% \hbar \omega /2$ per mode, which ---in contrast with \textsc{qed}--- is taken here as a primordial real entity in permanent interaction with matter and responsible for its quantization. After briefly recalling how quantum mechanics itself emerges as a result of the balance between the \textsc{zpf} and radiation reaction, the most important higher-order effects of the radiative terms on the atom are studied. The nonrelativistic \textsc{qed} formulas for the lifetimes and the Lamb shift, as well as the corrections to the latter due to external factors that modify the vacuum field, are thus obtained in a self-consistent approach and without the need to resort to second quantization to the present order of approximation.