On Fermi’s theory of β-decay

Summary

Planck’s derivation of the formula for the number of oscillators per unit volume, together with the relation between the frequency and the natural line width, suggest that a factor of the order of magnitude α⁻³ may have to be introduced in Fermi’s expression for the transition probability in the theory of β-decay. The new value for Fermi’s constantg is such that we obtain satisfactory aggreement between Konopinski-Uhlenbeck’s conclusions concerning the intensity distribution of β-ray spectra and the results of Heisenberg’s and Iwanenko’s application of Fermi’s theory to the production of electron showers by cosmic rays and the interaction of heavy particles respectively.