Photon structure functions and azimuthal correlations of lepton pairs in tagged γγ collisions

The reactions e+e−→ e+e−e+e− and e+e−→ e+e−μ+μ−, in a single tag configuration, are studied at LEP with the L3 detector. The data set corresponds to an integrated luminosity of 93.7 pb−1 at s=91 GeV. Differential cross sections are measured for 1.4GeV2≤Q2≤7.6GeV2. The leptonic photon structure function Fγ2 and azimuthal correlations are measured for e+e−→ e+e−μ+μ−. The related structure functions FγA and FγB, which originate from interference terms of the scattering amplitudes, are determined for the first time.