Selected Citation
Electron-Neutrino Angular Correlation in the Beta-Decay of He6
The recoil nuclei emitted during the beta-decay of He6 have been detected by means of an electron multiplier tube, and the beta-rays counted by means of an end window Geiger counter. The energy spectrum of the recoils has been studied by recording coincidences between the two detectors as a function of the retarding potential between a set of grids in the path of the recoils. Beta-recoil ion coincidences have been observed when the angle between the directions of emission of the beta-particle and of the recoil ion was 180 degrees and also 162 degrees. In both cases the best agreement was obtained when. the recoil spectra were compared with the curves predicted by the 1 — cost electron-neutrino angular correlation.
The results of this experiment seem to rule out the "no neutrino" assumption and give some indication of agreement with the 1 —(v/3c) cos8 correlation predicted by the axial vector form of interaction which follows Gamow-Teller selection rules. As mentioned above, the He6 decay is expected to be governed by this type of selection rule. It is hoped that further experiments with He' will lead to a more critical choice of the appropriate beta-interaction or combination of interactions.