Bai, JZ (reprint author), Inst High Energy Phys, Beijing 100039, Peoples R China.
Purely leptonic decays of the charged D meson have been studied using the reaction e(+)e(-) --> D*D-+(-) at a center of mass energy of 4.03 GeV. A search was performed for D --> mu v(mu), recoiling against a D-0 or D+ which had been reconstructed from its hadronic decay products. A single event candidate was found in the reaction e(+)e(-) --> D*D-+(-), where D*(+) --> pi(+)D(0) with the D-0 --> K- pi(+), and the recoiling D- decaying via D- --> mu(-)(v) over bar(mu). This yields a branching fraction value (D --> mu v mu) = 0.08(- 0.05 - 0.02)(+ 0.16 + 0.05)% and a corresponding value of the pseudoscalar decay constant f(D) = 300(- 150 - 40)(+ 180 + 80) MeV. (C) 1998 Elsevier Science B.V. All rights reserved.