We present a measurement of Γ(Ds+→μ+ν) Γ(Ds+→φπ+)=0.245±0.052±0.074. Using this ratio and B(Ds+→φπ+)=(3.7±0.9)% we extract fDs= 344±37±52±42 MeV, where the last error is due to the uncertainty in the Ds+→φπ+ absolute branching ratio. This result is larger than most theoretical predictions.
ASJC Scopus subject areas
- Nuclear and High Energy Physics