STRUCTURE FUNCTIONS OF LONGITUDINAL VIRTUAL PHOTONS AT LOW VIRTUALITIES

The structure functions F-1(L) and F-2(L) of longitudinal virtual phot ons at low virtualities are calculated in the framework of chiral pert urbation theory (ChPT) in the zero and first order of ChPT. It is assu med that the virtuality of a target longitudinal photon p(2) is much l ess than the virtuality of the hard projectile photon Q(2) and both ar e less than the characteristic ChPT scale. In this approximation the s tructure functions are determined by the production of two pions in ga mma gamma collisions. The numerical results for F-2(L) and F-1(L) are presented (the upper index refers to the longitudinal polarization of the virtual target photon). The possibilities of measurements of these structure functions are briefly discussed.