Measurement of B(D+ -> mu+ nu) and the pseudoscalar decay constant f_D at CLEO

The analysis of 60 1/pb data collected on the psi(3770) resonance with the CLEO-c detector has produced the first statistically significant signal for D+ -> mu+ nu decay and led to the measurement of the decay branching fraction B(D+ -> mu+ nu) = (3.5 +- 1.4 +- 0.6) x 10-4 and the pseudoscalar decay constant f_D = (202 +- 41 +- 17) MeV.Comment: Talk presented at the 1st Meeting of the APS Topical Group on Hadronic Physics (Fermilab, Oct. 24-26, 2004). LaTeX 4 pages, 2 figure