PHOTON STRUCTURE FUNCTIONS - TARGET PHOTON MASS EFFECTS AND QCD CORRECTIONS

We present a systematic analysis of the polarized and unpolarized proc esses e(+)e(-) --> e(+)e(-)X in the deep inelastic limit and study the effect of target photon mass (virtuality) on the photon structure fun ctions. The effect of target photon virtuality manifests itself as new singly polarized structure functions, and also alters the physical in terpretation of the unpolarized structure functions. The physical inte rpretation of these structure functions in terms of hadronic component s is studied using the free field analysis. We also retrieve the real photon results in the limit where the virtuality goes to zero. Assumin g factorization of the photon structure tensor, the relevant QCD corre ctions to the various twist 2 structure functions are evaluated.