We extract a relatively precise value for the decay constant of the D+ meson by measuring B(D+→μ+ν)=(4.40±0.66-0.12+0.09)×10-4 using 281pb-1 of data taken on the ψ(3770) resonance with the CLEO-c detector. We find fD+=(222.6±16.7-3.4+2.8)MeV, and compare with current theoretical calculations. We also set a 90% confidence upper limit on B(D+→e+ν)<2.4×10-5 which constrains new physics models.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)