Twist-3 Effects in Polarized Photon Structure *

In recent years there has been growing interest in the polarized photon structure functions. Especially the first moment of a photon structure function g 1 has attracted much attention in connection with the axial anomaly which is also relevant in the nucleon spin structure function g p(n) 1 . The polarized structure function g γ 1 could be experimentally studied in the polarized version of ep collider HERA, or more directly measured by the polarized ee collision in the future linear collider. And the next-to-leading order QCD analysis of g 1 has been recently performed in the literature. Now there exists another structure function g 2 for the virtual photon target, where the twist-3 effect is also relevant in addition to the usual twist-2 effect. In this talk, we investigate the twist-3 effects in g 2 , to the leading order in QCD, and show that it is a sizable effect in contrast to the nucleon case, where it appears to be small in the experimental data.