# P. Stahelin

## Determination of the Beta-Decay Interaction from Electron-Neutrino Angular Correlation Measurements

## Determination of the Gamow-Teller Beta-Decay Interaction From the Decay of Helium-6

__The electron-neutrino angular correlation coefficient has been measured for the negatron decay of He6 using the same apparatus x previously employed to determine the angular correlations in the positron decays of A35 and Ne19. __He6 decays with a half-life' of 0.85 sec by beta-particle emission to Li6 with a maximum beta energy of 3.5 Mev and a spin change delta I = 1 with no change in the nuclear parity. x Thus, He6 obeys only the rules for allowed Gamow-Teller decay and the angular correlation coefficient lambda.

## Electron-Neutrino Angular Correlation in the Positron Decay of Argon 35

In view of this rather unexpected result, a review of the existing data on the angular correlation coefficient of the positron emitter Ne19 may be interesting. For comparison with the A35 results, the experimental values and the theoretical limits of X for Ne" are plotted in the lower half of Fig. 2. It is evident, that in the case of Ne", the experimental values of A.