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 β-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 β-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 combined measurement of the polarization and resonance scattering of the γ-ray emitted after Κ- capture in Eu152 indicates a left-handed helicity for the neutrino, assuming the reasonably well-established spin-zero assignment for Eu152m.