Lamb shift: Additional recoil corrections and estimates of radiative proton effects

Abstract

Some new corrections to the hydrogen Lamb shift from multiphoton exchange graphs have been calculated and found to be 1 kHz. Radiative corrections to the proton line have also been considered for diagrams containing two exchanged Coulomb interactions and have been found to be of the order of $Z^2$α(Zα${)}^5$ $m^3$/$M^2$ and therefore negligible.