We investigate the effects of acceleration on the energy-level shifts of a hydrogen atom interacting with the electromagnetic field and in the presence of an infinite perfectly conducting plate. We consider the contributions of vacuum fluctuations and of the radiation reaction field to the Lamb shift, and we discuss their dependence from the acceleration of the atom. We show that, because of the presence of the boundary, both vacuum field fluctuations and radiation reaction field contributions are affected by atomic acceleration. In particular, the effect of the vacuum field fluctuations on the energy-level shifts is not equivalent to that of a thermal field. We also discuss the dependence of the Lamb shift from the orientations of the atomic dipole. We show that, for specific orientations of the atomic dipole, the atomic level shifts contain an extra contribution, as compared with the case of an atom at rest, suggesting the possibility to detect the effects of the acceleration for atoms with anisotropic polarizability.

• Received 16 April 2009

DOI:https://doi.org/10.1103/PhysRevA.79.062110