The Shapes of Negative Beta-Spectra at the Low Energy End

The disposition of the excess atomic binding energy liberated in a negative beta-decay is of interest in connection with the shape of the low energy end of the beta-spectrum. Previous theoretical work points to the carrying away of this energy by the beta-particle in most cases, with a resulting practical cutoff at the low end of the energy spectrum. However, the present approach, in which the nuclear and atomic electron transitions are treated as a unified process, leads to the conclusion that to the first order that shape is practically unaffected. A possibility for experimental study of this question is pointed out.