The real photon structure functions in massive parton model in NLO

Abstract

We investigate the one-gluon-exchange ($\alpha {\alpha }_s$) corrections to the real photon structure functions $W_{TT}$, $W_{LT}$, $W_{TT}^a$ and $W_{TT}^{\tau }$ in the massive parton model. We employ a technique based on the Cutkosky rules and the reduction of Feynman integrals to master integrals. We show that a positivity constraint, which is derived from the Cauchy-Schwarz inequality, is satisfied among the unpolarized and polarized structure functions $W_{TT}$, $W_{TT}^a$ and $W_{TT}^{\tau }$ calculated up to the next-to-leading order in QCD.

Comments: arXiv admin note: text overlap with arXiv:1110.2625