Virtual photon structure functions to the next-to-next-to-leading order in QCD
Virtual photon structure functions to the next-to-next-to-leading order in QCD
We investigate the unpolarized virtual photon structure functions ${F}_{2}^{\ensuremath{\gamma}}(x,{Q}^{2},{P}^{2})$ and ${F}_{L}^{\ensuremath{\gamma}}(x,{Q}^{2},{P}^{2})$ in perturbative QCD for the kinematical region ${\ensuremath{\Lambda}}^{2}\ensuremath{\ll}{P}^{2}\ensuremath{\ll}{Q}^{2}$, where $\ensuremath{-}{Q}^{2}$ ($\ensuremath{-}{P}^{2}$) is the mass squared of the probe (target) photon and $\ensuremath{\Lambda}$ is the QCD scale parameter. Using the framework of the operator product expansion supplemented by the renormalization …