Versuch einer Theorie der ß-Strahlen in Zeitschrift für Physik 88, 1934, pp. 161-177 [FERMI INTERACTION; 1st COMPLETE THEORY of BETA DECAY]

FIRST EDITION of the "Fermi Interaction," -- his seminal quantum mechanical description of the first complete theory of beta decay. "A particularly elegant theory and paper, Fermi's work is regarded as classic and remains highly influential to this day" (Peacock, The Quantum Revolution, 94).

"In 1930, Pauli postulated the existence of the neutrino to explain the continuous distribution of energy of the electrons emitted in beta decay. ["Fermi in 1931 jocularly dubbed the new particle the ‘neutrino.'" (ibid.)] Only with the emission of a third particle could momentum and energy be conserved" (Nave). Assuming the existence of the neutrino which Pauli had suggested to preserve the principle of conservation of energy, Fermi treated the ejection of electrons and neutrinos from a nucleus by a method similar to the radiation theory of photon emission from atoms.

Treating the beta decay as a transition that depended upon the strength of coupling between the initial and final states, Fermi developed a relationship which is now referred to as Fermi's Golden Rule. "Straightforward in concept, Fermi's Golden Rule says that the transition rate is proportional to the strength of the coupling between the initial and final states factored by the density of final states available to the system" (hyperphysics.edu).

"Fermi's theory, aside from bolstering Pauli's proposal of the neutrino, has a special significance in the history of modern physics. One must remember that only the naturally occurring beta emitters were known at the time the theory was proposed. Later when positron decay was discovered, the process was easily incorporated within Fermi's original framework. On the basis of his theory, the capture of an orbital electron by a nucleus was predicted and eventually observed. With time much experimental data has accumulated. Although peculiarities have been observed many times in beta decay, Fermi's theory always has been equal to the challenge.

"To appreciate the impact produced by Fermi's theory of beta decay on modern physics, one may note that it is rather amazing what varieties of observed phenomena (and what thicknesses of the Physical Review) are based on his one paper on the subject" (Wilson, Fermi's Theory of Beta Decay, AJP 36, 12, 1968). CONDITION & DETAILS: Berlin: Julius Springer. Ex-libris bearing two small stamps on the title page and a number at the foot of the index, otherwise clean throughout - inside and outside. (9 x 6.5 inches; 225 x 163mm). Recently rebound in black cloth; gilt-lettered at the spine. New endpapers. Tightly and very solidly bound. Bright and clean inside and out. Near fine.