The cross section for e+e-→ρπ has been measured by the BES detector at BEPC at center-of-mass energies covering a 40 MeV interval spanning the J/ψresonance. The data are used to search for the vector gluonium state hypothesized by Brodsky, Lepage, and Tuan as an explanation of the ρπ puzzle in charmonium physics. The shape of the ρπ cross section is compatible with that of the total hadronic cross section. No distortions indicating the presence of a vector glueball are seen. © 1996 The American Physical Society.

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 → μνμ recoiling against a D0 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*+ → π+D0 with the D0 → K-π+, and the recoiling D- decaying via D- → μ-ν̄μ. This yields a branching fraction value B(D → μνμ) = 0.08+0.16+0.05-0.05-0.02%, and a corresponding value of the pseudoscalar decay constant fD = 300+180+80-150-40 MeV. © 1998 Elsevier Science B.V. All rights reserved.