The polarized gluon distribution and its determination in p↘p↘→γ(large‐p_T)+X

Higher order (next‐to‐leading) corrections to p↘p↘→γ+X at large p_T are computed and K‐factors exceeding 1 are found. The cross sections peak at pseudorapidity η≂1. Asymmetries are also determined, and at η≂1 are shown to be very sensitive to the size of the polarized gluon distribution. Various schemes defining the Dirac matrix γ₅ in n≠4 dimensions are also discussed.