beta decay

Attempt at a Theory of β Rays

E. Fermi
Zeitschrift fur Physik
Jan 16 1934

Fermi introduces theory of beta decay, including supposition of the neutrino. Translation published by Fred L. Wilson in the American Journal of Physics, Dec. 1968.

Theory of the classical Beta-Decay Measurements

E. J. Konopinski
Proceedings of the Rehovot Conference on Nuclear Structure
Sep 10 1957

Recent developments have forced the generalization of the beta interaction to the inclusion of odd with even couplings. Two further kinds of generalizations must also be considered until definite experimental decision are available: the possibility that time-reversal invariance does not hold (that the coupling constants are complex) and the possibility that “lepton conservation” fails (both neutrinos and anti-neutrinos are emitted in a given process).

Introduction. The category of “classical “ measurements on nuclear beta-decay is introduced here as a distinction convenient for this conference. Newer experiments, which have exhibited the failure of parity conservation (as formerly understood), are to receive separate and fuller discussion by the authors of that development themselves. Here we shall be primarily concerned with interpretations of data from longer established lines of experimentation, hence “classical” ones.

7. Conclusions from Electron-Recoil Correlations. The electron-neutrino correlation measurements are relied upon to distinguish between the scalar and vector forms of the Fermi coupling, and between the tensor and axial vector forms of GT coupling.

The earliest definitive measurement, by Rustad and Ruby, yielded aGT > 0.16 and

Before the A35 measurement was announced, it was consider most probable that all the GT radiation is generated by tensor coupling, all the Fermi radiation by scalar coupling. This corresponds to the straight line labelled S,T in Fig 2. However that conclusion was upset by the A35 result, which demands that the scalar coupling constitute no more than the fraction e of the Fermi radiation! In view of the near isotropy of the neutron and Ne19 recoils, the He6 and A35 results appear to be irreconcilable

Favoring the conclusions from Ne23 (vs. He6) is the fact that it brings into consistency all the results except that on He6. One the other hand, the He6 experiment should be the most nearly ideal one. For the present, one must keep in mind two possible resolutions of the situation: [2 equations]. It seems to early to choose between these.

Post-Conference Summary of Recent Developments in Beta-Decay

H. J. Lipkin
Proceedings of the Rehovot Conference on Nuclear Structure
Jan 1 1958

Added in proof
Reports on “non-classical recoil experiments” including Goldhaber, Grodzins, Sunyar


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.

Electron-Neutrino Correlation

P. E. Cavanagh
Proceedings of the Rehovot Conference on Nuclear Structure
Sep 10 1957

Report on Ridley experiment with discussion


This appears to be in serious disagreement with the result obtained by Ruby and Rustad.
As mentioned by Professor Konopinski, if this point is potted on the Scott diagram, taken in conjunction with the Ne19 and A35 results, it suggests either a (V,A) or (V,T,A) interaction.


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