Light mesons and strange particle production at HERA

Results on the ρ0(770), K∗0(892), φ(1020), K0 S and Λ production in ep collisions at HERA obtained with H1 and ZEUS detectors are presented. Properties of the light mesons are investigated using photoproduction events and those of the strange particles are studied using the deepinelastic scattering events. Photoproduction of light mesons, ρ0, K∗0 and φ , at the average γ p centre-of-mass energy of 210 GeV and in particular the transverse momentum spectra are studied by H1 Collaboration. The K0 S and Λ production is evaluated in different regions of the exchanged photon virtuality, Q2. Low 2 < Q2 < 100 GeV2 and high 145 < Q2 < 20000 GeV2 regions are investigated by H1, whereas the 10 < Q2 < 40000 GeV2 region by ZEUS experiment. The differential cross sections for K0 S and Λ production measured by H1 in the laboratory and Breit frames are compared to the leading order Monte Carlo predictions. Results of the ZEUS Collaboration studies of the scaled momentum distributions of K0 S and Λ particles in the Breit frame current fragmentation region in the context of the hadronisation investigation in ep collisions are presented. The data are compared to the leading-logarithm parton-shower Monte Carlo models and next-to-leading order QCD calculations.