Measurement of B(D_s+ -> mu+ nu_mu)/B(D_s+ -> phi mu+ nu_mu) and Determination of the Decay Constant f_{D_s}
hep-ex
/ Authors
K. Kodama, S. Torikai, N. Ushida, A. Mokhtarani, V. S. Paolone, J. T. Volk, J. O. Wilcox, P. M. Yager, R. M. Edelstein, A. P. Freyberger
and 64 more authors
D. B. Gibaut, R. J. Lipton, W. R. Nichols, D. M. Potter, J. S. Russ, C. Zhang, Y. Zhang, H. I. Jang, J. Y. Kim, B. R. Baller, R. J. Stefanski, K. Nakazawa, S. H. Chung, M. S. Park, I. G. Park, J. S. Song, C. S. Yoon, M. Aryal, N. W. Reay, R. A. Sidwell, N. R. Stanton, S. Yoshida, M. Chikawa, T. Hara
/ Abstract
We have observed $23.2 \pm 6.0_{-0.9}^{+1.0}$ purely-leptonic decays of $D_s^+ -> μ^+ ν_μ$ from a sample of muonic one prong decay events detected in the emulsion target of Fermilab experiment E653. Using the $D_s^+ -> φμ^+ ν_μ$ yield measured previously in this experiment, we obtain $B(D_s^+ --> μ^+ ν_μ) / B(D_s^+ --> φμ^+ ν_μ) =0.16 \pm 0.06 \pm 0.03$. In addition, we extract the decay constant $f_{D_s}=194 \pm 35 \pm 20 \pm 14 MeV$.