Testing QCD in Photon-Photon Interactions
  At high energies photon-photon interactions are dominated by quantum fluctuations of the photons into fermion-antifermion pairs and into vector mesons. This is called photon structure. Electron-positron collisions at LEP are an ideal laboratory for studying photon structure and for testing QCD. 
Stefan Soldner-Rembold (Freiburg University)