Muon production in e+e- annihilation at high energies

The production of muons has been measured using the TASSO detector at the high energy e+e- colliding beam facility. PETRA. The reaction e+e- → μ+μ- has been studied at centre of mass energies, W, between 12.0 and 36.7 GeV. At high energies (W approximately equal to 33 GeV) the ratio of the measured cross-section to the QED prediction was found to be 0.89 +-0.09 and the forward-backward muon asymmetry (-6.0 +-9.0) %. μμγ final states have been measured and their production rate and properties found to be consistent with QED hard photon bremsstrahlung. A conventional top quark has been searched for via its muonic decay and no evidence for its production found. (author)