Particle production at HERA

Results on particle production in deep-inelastic scattering in ep collision at HERA, obtained with the H1 and ZEUS detectors, are presented. The underlying parton dynamics is investigated by studying the transverse momentum distribution of charged particles and comparing the measurements with various Monte Carlo generators using different approaches to simulate the parton cascade. In this context also results on forward jet production are discussed. The underlying parton dynamics is also studied using prompt photon production in both DIS and photoproduction regimes. The production is compared to theoretical calculations and Monte Carlo predictions. In the context of hadronisation, studies are presented of the scaled momentum distribution for charged hadrons and for and Λ particles in the current fragmentation region of the Breit frame. The data are compared to models and to next-to-leading order QCD calculations. In addition, differential cross sections for production in the laboratory and Breit frame are investigated and compared to Monte Carlo predictions, which are used to study the flavour decomposition and strangeness suppression factor. production is also compared to the production of charged particles and to the production rate of the DIS events.