Charm production in deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 120 pb^{ -1}. The hadronic decay channels D^{ +} -> K^{ 0}_{ S} pi^{ +}, Lambda_{ c}^{ +} -> p K^{ 0}_{ S} and Lambda_{ c}^{ +} -> Lambda pi^{ +}, and their charge conjugates, were reconstructed. The presence of a neutral strange hadron in the final state reduces the combinatorial background and extends the measured sensitivity into the low transverse momentum region. The kinematic range is 0 < p_{ T}(D^{ +}, Lambda_{ c}^{ +}) < 10 GeV, |eta(D^{ +}, Lambda_{ c}^{ +})| < 1.6, 1.5 < Q^{ 2} < 1000 GeV^{ 2} and 0.02 < y < 0.7. Inclusive and differential cross sections for the production of D^{ +} mesons are compared to next-to-leading-order QCD predictions. The fraction of c quarks hadronising into Lambda_{ c}^{ +} baryons is extracted.
Categories: hep-ex