1110.2625 (Norihisa Watanabe et al.)

The polarized photon structure function $g_1^γ(x,Q^2)$ in massive
parton model in NLO    [PDF]

Norihisa Watanabe, Yuichiro Kiyo, Ken Sasaki

We investigate the one-gluon-exchange ($\alpha \alpha_s$) corrections to the polarized real photon structure function $g_1^\gamma(x,Q^2)$ in the massive parton model. We employ a technique based on the Cutkosky rules and the reduction of Feynman integrals to master integrals. The NLO contribution is noticeable at large $x$ and does not vanish at the threshold of the massive quark pair production due to the Coulomb singularity. It is found that the first moment sum rule of $g_1^\gamma$ is satisfied up to the NLO.

View original: http://arxiv.org/abs/1110.2625