Parton Distributions from Photoproduction in Polarized ep Scattering at HERA

We study photoproduction of jets and single-inclusive hadrons in a polarized ep collider mode of HERA at √ s ≈ 300 GeV, examining the sensitivity of the cross sections and their asymmetries to the proton’s polarized gluon distribution and to the completely unknown parton distributions of polarized photons. We also present for the first time the NLO corrections to the direct part of polarized single-inclusive hadron photoproduction.