SEARCH FOR DELTAQ=-DELTAS TRANSITIONS IN SIGMA-HYPERON DECAYS

In a sample of 106Σ+ hyperons we have searched for the decays σ+→ ne+ν and σ+→nμ+ν, which would violate the ΔQ=ΔS rule. No Σ+→ne+ν decay was found, whereas 313 σ-→ne-ν decays were identified in the same film. With 90% confidence we obtain {Mathematical expression} Having found two candidates for the decay σ+→nμ+ν and 104 Σ-→nμ-ν events we obtain for the muonic mode {Mathematical expression} The probability that the μ+-events are simulated by σ+→nπ+γ with subsequent undetected π+→μ+ν decay is less than 4%. © 1969 Springer-Verlag.