Inclusive Muon Production in e^{+}e^{-} Annihilation with 〈s^{1/2}〉=7.3 GeV

We present results on charged multiplicity nch=2 and nch>2 muon events produced in e+e- collisions with 〈s1/2〉=7.3 GeV at 90° to the beams. The background-subtracted inclusive cross section for the nch=2 events is 10.2±5.4 pb/sr, in agreement with the expected contribution from the heavy lepton τ. The cross section for the nch>2 events is 19.0±6.5 pb/sr whereas we expect only 2.9 pb/sr from the τ, indicating that we may be seeing the weak decays of charmed mesons.