Chronology of Milestone Events in Particle Physics - TAMM 1930
Chronology of Milestone Events in Particle Physics

TAMM 1930

Tamm, I.E.;
On Free Electron Interaction with Radiation in the Dirac Theory of the Electron and in Quantum Electrodynamics
Z. Phys. 62 (1930) 545;

Reprinted in
(translation into Russian) I. E. Tamm, Sobranie nauchnykh trudov, Nauka Moskva, 1975, t. II, s. 24.

Dirac's wave equations are used to determine the wave functions of the free election (a simple method for manipulating these wave functions is introduced) and the radiation field is also quantized. In this way a formula is derived for the scattered radiation from free electrons which is identical with the Klein-Nishina result, but which does not rest on an appeal to the correspondence principle to evaluate the radiated intensity from the distribution of the electron current. It appears that quantum jumps to intermediate states of negative energy play a determining part in the scattering process. In addition, the probability of a spontaneous transition of an electron from a positive to a negative energy level is evaluated and shown to equal to the classically estimated probability of collision between two electrons of relative velocity c. Such a transition would correspond in Dirac's recent theory of the proton to the transformation of the matter of the electron and proton into radiation. Applying the result obtained to an atom, an impossibly short life period for the atom is obtained (of the order 10-3 sec), and this appears to be a fundamental difficulty for the new Dirac theory of the proton if the assumptions of the present analysis are justified. (Science Abstracts. 1930. 3645. W. S. S.).

Related references
More (earlier) information appears in
I. E. Tamm, Z. Phys. 60 (1930) 345;
See also
O. Klein, Z. Phys. 41 (1927) 407;
O. Klein, Z. Phys. 53 (1929) 157;
O. Klein and Y. Nishina, Z. Phys. 52 (1928) 853;
E. Fermi, Rend. Accad. nat. Lincei 31 (1922) 184;
P. A. M. Dirac, Proc. Roy. Soc. A114 (1927) 243;
P. A. M. Dirac, Proc. Roy. Soc. A114 (1927) 710;
P. A. M. Dirac, Proc. Roy. Soc. A117 (1928) 610;
W. Heisenberg and W. Pauli, Z. Phys. 56 (1929) 1;
E. Schrödinger, Annalen der Physik. Leipzig 81 (1926) 109;
P. A. M. Dirac, Proc. Roy. Soc. A126 (1930) 360;

  e e cs

Particles studied
  e+ ex
  p qn

Record comments
Difficulties with identifying positive holes with protons in the Dirac theory of electrons and protons. Too small a lifetime of the ordinary atom.
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