Virtual Photon Structure Functions to NNLO in QCD

The unpolarized virtual photon structure functions and are investigated in perturbative QCD for the kinematical region Λ2≪P2≪Q2, where −Q2(−P2) is the mass squared of the probe (target) photon and Λ is the QCD scale parameter. In the framework of operator product expansion supplemented by the renormalization group method, the definite predictions are derived for the moments of up to the next-to-next-to-leading order (the order ααs) and for the moments of up to the next-to-leading order (the order ααs).