This work was partially supported by the National Aeronautics and Space Administration under Grant No. NAG1442.
Physical Review A
Quantum theory, Momentum transfer
Relativistic corrections to order alpha² to the Bethe sum rule have been obtained for a one-electron system employing the Foldy-Wouthuysen transformation. The results have wide applications in high-Z systems at large momentum transfers.
Leung, P. T., Rustgi, M. L., & Long, S. T. (1986). Relativistic corrections to the Bethe sum rule. Physical Review A (General Physics), 33(4), 2827-2829.