Selected Citation
POST-CONFERENCE SUMMARY OF RECENT DEVELOPMENTS IN BETA-DECAY
Results presented at the conference indicated the need for further experiments involving measurement of the direction of neutrino emission in order to distinguish between the ß-interactions S–T and V–A. Within a few months the new "non-classical recoil experiment" has been developed, in which the polarization of radiation following ß-decay is measured relative to the direction of the recoil. The principal difficulty of recoil experiments, namely that of determining the direction of the recoil, has been overcome in a very ingenious way, using the Doppler effect required for resonance scattering of nuclear γ-rays. The result of a cominbined measurement of the polarization and resonance scattering of the γ-ray emitted after K– capture in Eu152m indicates a left-handed helicity for the neutrino, assuming the reasonably well-established spin-zero assignment for Eu152m.
The implications of these results can now be combined with the conclusions of Adler's summary (Session VI) by adding to his list of experiments: V. Non-classical recoil experiments.
,This in combination with the polarization results (Alder I), indicates that the G-T interaction is A, in direct contradiction with results of classical recoil experiments for He6 and Ne19. The observed interference between the Fermi and GT-parts of the interaction in ß-γ polarization correlation experiments (Alder II) leads to the consulsion that if the FT-interaction is A, the Fermi interaction must be V.
The A and V assignments are in agreement with two-component theory and also with other new theories. [Sudarshan-Marshak and Feynman-Gell-Man are cited.]