NNLO QCD analysis of the virtual photon structure functions

Abstract

The next-to-next-to-leading order (NNLO) QCD analysis is performed for the virtual photon structure functions which can be measured in the double-tag events in two-photon processes in $e^+e^-$ collisions. We investigate the perturbative QCD evaluation of $F_2^γ(x,Q^2,P^2)$ to NNLO and $F_L^γ(x,Q^2,P^2)$ to NLO with and without taking into account the target mass effects, which are relevant for the large $x$ region. We also carry out the phenomenological analysis for the experimentally accessible effective structure function $F_{\rm eff}^γ=F_2^γ+(3/2)F_L^γ$.

5 pages, 6 eps figures, uses PoS.cls, Proceedings of RADCOR 2007 (Florence)