Hydrogen energy levels from the anomalous energy-momentum QED trace

Abstract

Energy levels of hydrogen are calculated as one-loop matrix elements of the QED energy-momentum tensor trace in the external field approximation. An explicit connection established between the one-loop trace diagrams and the standard Lamb shift one-loop diagrams. Our calculations provide an argument against inclusion of the anomalous trace contribution as a separate term in the decomposition of the QED quantum field Hamiltonian and serve as an illustration how the trace anomaly is realized in the bound state QED.

Comments: 35 pages, 10 figures;v2:Minor amendments, discussion of the results expanded, additional references and acknowledgments added, results unchanged; v3: Abstract amended; v4: published version