The structure of diffraction and the diffractive hadronic final states in ep collisions at HERA

Recent measurements of diffractive processes at HERA, which test the QCD factorization in high energy diffractive DIS (DDIS) and photoproduction (γ∗p) hard scale processes are compared to leading order (LO) and next to leading order (NLO) predictions. QCD factorization is seen to hold for D∗ production, both in DDIS and photoproduction, as well as for dijets in DDIS, but fails for dijets in photoproduction.