Observation of the Decay Xi^0 --> Sigma^+ mu^- nu(bar)

TL;DR

This paper reports the first observation of the Xi^0 --> Sigma^+ mu^- nu decay, measuring its rate relative to a known decay, confirming predictions of the SU(3) flavor symmetry model.

Contribution

First experimental observation of the Xi^0 muon semi-leptonic decay with quantitative rate measurement at Fermilab.

Findings

Decay observed with nine events

Decay rate ratio measured as approximately 1.8%

Results agree with SU(3) flavor symmetry predictions

Abstract

The Xi^0 muon semi-leptonic decay has been observed for the first time with nine identified events using the KTeV beam line and detector at Fermilab. The decay is normalized to the Xi^0 beta decay mode and yields a value for the ratio of decay rates of $(1.8^{+0.7}_{-0.5}(stat.)\pm0.2(syst.))\times 10^{-2}$. This is in agreement with the SU(3) flavor symmetric quark model.