We report on a measurement of the decay KL→μ+μ-γ from Fermilab experiment E799. We observe 207 candidate signal events with an estimated background of 10.5±4.0 events and establish B(KL→μ+μ-γ)=[3.23±0.23(stat)±0.19(syst)] ×10-7. This provides the first measurement of the Kγγ* form factor in the muonic Dalitz decay mode of the KL.
ASJC Scopus subject areas
- Physics and Astronomy(all)