Azimuthal correlations in photoproduction and deep inelastic $ep$ scattering at HERA

Recent results from the ZEUS Collaboration are presented on the features of multiparticle correlations in photoproduction in $ep$ collisions at HERA. They are compared to correlations observed in deep inelastic $ep$ scattering and to earlier results in heavy-ion collisions at the LHC. No evidence for quark-gluon plasma formation is seen at HERA. Detailed correlaton coefficients are compared to various models, and it is concluded that multiparton collisions form an important part of the photoproduction process.