Resolved ${\gamma }_{\mathbf{L}}^{\ast }$ in hard collisions of virtual photons: QCD effects

Abstract

The manifestations of QCD effects on quark and gluon distribution functions of longitudinally polarized virtual photons involved in hard collisions are investigated. It is shown that for moderate photon virtualities and in the kinematical region accessible at HERA and LEP these effects are sizable and significantly enhance theoretical predictions based on contributions of transversally polarized virtual photon only.

Comments: 7 pages, Latex using EPJ style, 8 eps figures