E. Leitner

Fit of the parameters for Cabibbo's theory

AbstractAll experimental data on leptonic decays of Baryons available after the Kiev Conference on High Energy Physics (Sept. 1970) are used to fit the parameters of the Cabibbo theory. Especially new results on σ− and Λ leptonic decays and the values of the Σ± lifetime are included.The data are consistent with the one angle Cabibbo theory. The results for the three parameters are:

Determination of the Σ± → Λe±ν decay parameters

\begin{gathered} \theta = 0.239 \pm 0.005 \hfill \\ g_1^F = 0.451 \pm 0.019 \hfill \\ g_1^D = 0.777 \pm 0.021. \hfill \\ \end{gathered}

Measurement of the Σ−→ne−¯v and Σ−→ nμ−¯v rates

AbstractThe decay modesΣ±→nπ±γ, Σ+→pγ,Σ+→pe+e}- were studied in the 81 cm Saclay hydrogen bubble chamber. In the radiative decayΣ±→nπ±γ only low momentum pions which stop in the chamber were accepted.We obtain the following branching ratios:(1)

A new fit of the parameters for Cabibbo's theory

\frac{{\Gamma {\text{(}}\sum ^{\text{ + }} \to n\pi ^ + \gamma , p_{\pi + }^*< 110{\text{ MeV/c)}}}}{{\Gamma {\text{(}}\sum ^{\text{ + }} \to n\pi ^ + )}} = (2.7 \pm 0.5) \times 10^{ - 4} ,

Possible violation of the δS=δQ selection rule in leptonic decays of σ+-hyperons

(2)