Selected Citation

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

Authors(s):W. B. Herrmannsfeldt, R. L. Burman, P. Stahelin, J. S. Allen, and T. H. Braid Publication:Physical Review Letters Publication Date:July 15, 1958 Publisher: American Physical Society Citation:Phys. Rev. Lett. 1, 61 (1958) Link:

The electron-neutrino angular correlation coefficient has been measured for the negatron decay of He6 using the same apparatus 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. should be either + 1/3 or -1/3 corresponding, respectively, to the tensor or axial-vector interaction. Our experimental result, lambda = -0.39 + 0.02, clearly indicates that the axial-vector interaction is dominant.

The results of the measurements indicated a single activity with a half-life of 0. 83 + 0. 02 sec, in good agreement with the value 0.85+ 0.03 sec given by Rustad and Ruby.


The measurements strongly support an axial vector-vector interaction for nuclear beta-decay, in agreement with other recent results, in quite different types of experiment.