Nobel prize to R. P. Feynman awarded in 1965. Co-winners J. S. Schwinger and S. Tomonaga "for their fundamental work in quantum electrodynamics, with deep-ploughing consequences for the physics of elementary particles''
A relativistic cut-off of high frequency quanta, similar to that suggested by Bopp, is shown to produce a finite invariant self-energy for a free electron. The electromagnetic line shift for a bound electron comes out as given by Bethe and Weisskopf's wave packet prescription. The scattering of an electron in a potential, without radiation, is discussed. The cross section remains finite. The problem of polarization of the vacuum is not solved. Otherwise, the results will in general agree essentially
with those calculated by the prescription of Schwinger. An alternative cut-off procedure analogous to one proposed by Wataghin, which eliminates high frequency intermediate states, is shown to do the same things but to offer to solve vacuum polarization problems as well.
Related references More (earlier) information appears in R. P. Feynman, Phys. Rev. 74 (1948) 939;
See also J. Schwinger, Phys. Rev. 73 (1948) 415A;
H. A. Bethe, Phys. Rev. 72 (1947) 339;
H. A. Bethe, Phys. Rev. 73 (1948) 1271A;
J. Schwinger and V. F. Weisskopf, Phys. Rev. 73 (1948) 1272A;
H. W. Lewis, Phys. Rev. 73 (1948) 173;
G. Wataghin, Z. Phys. 88 (1934) 92;
V. Weisskopf, Phys. Rev. 56 (1939) 72;
S. M. Dancoff, Phys. Rev. 55 (1939) 959;
F. Bloch and A. Nordsieck, Phys. Rev. 52 (1937) 54;
W. Pauli, Handbuch der Phys. 24/1 (1933) 233;
E. A. Uehling, Phys. Rev. 48 (1935) 55;
R. Serber, Phys. Rev. 48 (1935) 49;
Analyse data from F. Bopp, Annalen der Physik. Leipzig 42 (1942) 573;
Creation of the covariant theory of quantum electrodynamics. Feynman method.