Authors(s):Emil Jan Konopinski Publication:Reviews of Modern Physics Publication Date:October 1943 Publisher: American Physical Society Citation:Rev. Mod. Phys. 15, 209 Link:

The experiments which established the existence of naturally and artifcially radioactive emissions of negative and positive electrons by atomic nuclei and the critical calorimetric experiments which showed that part of the energy released during a P-decay process escapes in some yet undetected form were completed before 1933. In that year there was introduced the currently accepted picture of the P-process, in which Pauli's neutrino hypothesis occupies a central position. The assumption is that in the process a nucleon is transformed from a proton into a. neutron (or vice versa) with the simultaneous creation of a, positron (or negatron) and an (anti) neutrino. The latter particle is hypothesized to be the carrier of the missing energy and the failure to detect it after its emission is ascribed to its having no charge, probably no magnetic moment, and only small non-electromagnetic interactions with other particles.