Measurement of muon-pair production at 50GeV

Using the data recorded with the L3 detector at LEP, we study the process e(+)e(-) --> mu(+)mu(-)(gamma) for events with hard initial-slate photon radiation. The effective centre-of-mass energies of the muons range from 50 GeV to 86 GeV. The data sample corresponds to an integrated luminosity of 103.5 pb(-1) and yields 293 muon-pair events with a hard photon along the beam direction. The events are used to determine the cross sections and the forward-backward charge asymmetries at centre-of-mass energies below the Z resonance.