Photoproduction of Jets and Heavy Flavors at Future Polarized ep -   Colliders
  We study photoproduction of jets and heavy flavors in a polarized collider mode of HERA and in polarized $ep$ collisions at $\sqrt{S}\approx 30$ GeV. We examine the sensitivity of the cross sections and their asymmetries to the proton's polarized gluon distribution and to the completely unknown parton distributions of longitudinally polarized photons. 
M. Stratmann (Univ. Dortmund), W. Vogelsang (Rutherford)