Virtual Photon Structure Functions to NNLO in QCD

KUNS-2121 YNU-HEPTh-07-103 The unpolarized virtual photon structure functions F γ 2 (x,Q , P ) and F γ L(x,Q , P ) are investigated in perturbative QCD for the kinematical region Λ ≪ P 2 ≪ Q, where −Q(−P ) 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 F γ 2 (x,Q , P ) up to the next-to-next-toleading order (the order ααs) and for the moments of F γ L(x,Q , P ) up to the next-toleading order (the order ααs).