Published in:

Physical Review Letters 99,7 (2007)


We measure the decay constant f(Ds)(+) using the D-s(+)-> l(+)nu channel, where the l(+) designates either a mu(+) or a tau(+), when the tau(+)->pi(+)(v) over bar. Using both measurements we find f(Ds)(+)= 274 +/- 13 +/- 7 MeV. Combining with our previous determination of f(D)(+), we compute the ratio f(Ds)(+)/f(D)(+)= 1.23 +/- 0.11 +/- 0.04. We compare with theoretical estimates.


Physics, Multidisciplinary

Date of this Version

January 2007



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