We measure the decay constant fDs+ using the Ds+→+ν channel, where the + designates either a μ+ or a τ+, when the τ+→π+ν ̄. Using both measurements we find fDs+=274±13±7MeV. Combining with our previous determination of fD+, we compute the ratio fDs+/fD+=1.23±0.11±0.04. We compare with theoretical estimates. © 2007 The American Physical Society.
Artuso, M., Blusk, S., Butt, J., Khalil, S., Li, J., Menaa, N., … Yang, F. (2007). Measurement of the decay constant fDs+ using Ds+→l+ν. Physical Review Letters, 99(7). https://doi.org/10.1103/PhysRevLett.99.071802