Electron Polarization in Beta Processes

Abstract

Recent experiments have confirmed the hypothesis of Lee and Yang that there exist terms in the beta interaction which destroy the invariance of the theory under space inversion and charge conjugation; the possibility of the lack of invariance under time reversal had not yet been tested conclusively. We explore further consequences of these additional interactions, limiting the discussion to experiments involving the detection of polarized electrons and gamma rays from unpolarized nuclei. In particular, formulas are derived for the longitudinal polarization of electrons in beta decay, and for the correlation of the transverse polarization of electrons with the direction of a gamma ray. Such experiments would lead to an independent verification of the violation of selection rules for parity and charge conjugation, and to a possible test of the invariance under time reversal.