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 $F_2^{\gamma }(x,Q^2,P^2)$ to NNLO and $F_L^{\gamma }(x,Q^2,P^2)$ 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 $F_{\mathrm{eff}}^{\gamma }=F_2^{\gamma }+(3/2)F_L^{\gamma }$.

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